Some recent definitions
Professor Henry Smith, economics is “the study of how in a civilised society one obtains the share of what other people have produced and of how the total product of society changes and is determined.”
Prof. Samuelson, a Nobel Laureate in economics, defines economics as “the study of how societies use scarce resources to provide valuable commodities and distribute them among different people”
According to Jacob Viner “economics is what economists do”