Notwithstanding its acknowledged centrality in the economic process, entrepreneurship has been defined differently by different authors and individuals.
Entrepreneurship is a concept that is so protean in nature that it is virtually difficult to categorize it in a single acceptable definition. So much so that a well respected economist, Mark Casson once affirm that “entrepreneurship means different things to different people”.
Entrepreneurship appears in different sizes. It can be found in large corporations as well as small retail shops. It can present itself under various forms.
You may discover that it is the motivating force behind a scientist or technologist who assigns economic meaning to his or her laboratory activity. It is also to be found in the old-time peddler who was particularly able as a sales person just as today we can find it in highly-educated manager who oversees large corporations. And of course it is what pushes the impetuous, instinctive type who is able to anticipate demand and to build an economic empire.
Certainly, a good test to clarify if we are really dealing with entrepreneurship is the capacity to create something new. However, innovation cannot explain everything, since not all the people we tend to identify as entrepreneurs are exceptional innovators. The posts which follows are guides to notice when examining the definition of the concept of entrepreneurship.
The following are some useful definitions of entrepreneurship:
[Wikia:] Entrepreneurship is the act of being an entrepreneur, which is a French word meaning “one who undertakes innovations, finance and business acumen in an effort to transform innovations into economic goods”. This may result in new organizations or may be part of revitalizing mature organizations in response to a perceived opportunity.
The most obvious form of entrepreneurship is that of starting new businesses (referred as Startup Company); however, in recent years, the term has been extended to include social and political forms of entrepreneurial activity. When entrepreneurship is describing activities within a firm or large organization it is referred to as intra-preneurship and may include corporate venturing, when large entities spin-off organizations. 
[Wikipedia:] Entrepreneurship is the process of designing a new business, i.e. a startup company offering a product, process or service.  The entrepreneur perceives a new business opportunity and often exhibits biases in their perception and subsequent decision to exploit the opportunity.  The exploitation of entrepreneurial opportunities may include design actions such as to develop a business plan, acquire the human, financial and other required resources, and to be responsible for its success or failure.  Entrepreneurship may operate within an entrepreneurship ecosystem which includes government programs and services that promote entrepreneurs, entrepreneurship resources (e.g., business incubators and seed accelerators), entrepreneurship education, training and financing (e.g., loans, venture capital financing, and grants).
[BusinessDictionary:] The capacity and willingness to develop, organize and manage a business venture along with any of its risks in order to make a profit. The most obvious example of entrepreneurship is the starting of new businesses.
In economics, entrepreneurship combined with land, labor, natural resources and capital can produce profit. Entrepreneurial spirit is characterized by innovation and risk-taking, and is an essential part of a nation’s ability to succeed in an ever changing and increasingly competitive global marketplace.
According to Paul Reynolds, entrepreneurship scholar and creator of the Global Entrepreneurship Monitor, “by the time they reach their retirement years, half of all working men in the United States probably have a period of self-employment of one or more years; one in four may have engaged in self-employment for six or more years. Participating in a new business creation is a common activity among U.S. workers over their course of their careers.”  And in recent years has been documented by scholars such as David Audretsch to be a major driver of economic growth in both the United States and Western Europe.
Entrepreneurial activities are substantially different depending on the type of organization that is being started. Entrepreneurship ranges in scale from solo projects (even involving the entrepreneur only part-time) to major undertakings creating many job opportunities. Many “high value” entrepreneurial ventures seek venture capital or angel funding (seed money) in order to raise capital to build the business. Angel investors generally seek annualized returns of 20-30% and more, as well as extensive involvement in the business. Many kinds of organizations now exist to support would-be entrepreneurs, including specialized government agencies, business incubators, science parks, and some NGOs.
In more recent times, the term entrepreneurship has been extended to include elements not related necessarily to business formation activity such as conceptualizations of entrepreneurship as a specific mindset (see also entrepreneurial mindset) resulting in entrepreneurial initiatives e.g. in the form of social entrepreneurship, political entrepreneurship, or knowledge entrepreneurship have emerged.
Entrepreneurship is also a process that has to do with the conceptual approach to doing new things, within a new philosophy of value, purpose, utility, quality and use which satisfies needs.
Entrepreneurship is the process of creating something new with value, by devoting the necessary time and efforts, assuming the accompanying financial, psychological and social risks, and receiving the monetary rewards for monetary and personal independence.
From the last definition above, four basic aspects were emphasized:
- Creative process (physical outfit)
- A creation that has value (satisfaction of needs)
- A transaction that involves the risk factor which centres on psychological, financial and social areas (risk-taking) and
- A transaction that involves rewards to the entrepreneur (external or intrinsic rewards).
Entrepreneurship is therefore concerned with the identification of gaps and business opportunities in one’s immediate environment and bringing together the necessary resources in an innovative way to fill these gaps, bearing the risks involved and In the process gaming personal rewards.
Entrepreneurship is the willingness, ability or capacity of an individual to seek out investment opportunities, to establish and run enterprises successfully.
Entrepreneur is also the agent that brings together other factors of production chiefly through the medium of money, with a view to producing goods or services or both and with the primary aim of making profits. He is someone who is out to satisfy identified needs. An entrepreneur is always seen as an achiever.