It literally isn’t I’m afraid Napster.
It's short for "economical science".
Science is defined as "the intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment."
some historical definitions:
Sir James Steuart (1767) wrote the first book in English with 'political economy' in the title, explaining that just as: "Economy in general [is] the art of providing for all the wants of a family, [
so the science of political economy] seeks to secure a certain fund of subsistence for all the inhabitants, to obviate every circumstance which may render it precarious; to provide every thing necessary for supplying the wants of the society, and to employ the inhabitants ... in such manner as naturally to create reciprocal relations and dependencies between them, so as to supply one another with reciprocal wants."
The philosopher Adam Smith (1776) defines the subject as "an inquiry into the nature and causes of the wealth of nations," in particular as:a branch of
the science of a statesman or legislator [with the twofold objective of providing] a plentiful revenue or subsistence for the people ... [and] to supply the state or commonwealth with a revenue for the publick services."
J.B. Say (1803), distinguishing the subject from its public-policy uses, defines it as
the science of production, distribution, and consumption of wealth.
John Stuart Mill (1844) defines the subject in a social context as:
The science which traces the laws of such of the phenomena of society as arise from the combined operations of mankind for the production of wealth, in so far as those phenomena are not modified by the pursuit of any other object.
William Stanley Jevons.. defines economics highlighting the hedonic and quantitative aspects of the science: "In this work I have attempted to treat Economy as a Calculus of Pleasure and Pain, and have sketched out, almost irrespective of previous opinions, the form [B}which the science[/B], as it seems to me, must ultimately take. I have long thought that as it deals throughout with quantities, it must be a mathematical science in matter if not in language.
Lionel Robbins (1932) developed implications of what has been termed "[p]erhaps the most commonly accepted current definition of the subject":[12]
Economics is
a science which studies human behaviour as a relationship between ends and scarce means which have alternative uses.[13]
I know you think that science is probably that which can be repeated and observed but for a more analytical science like economics, it's different. It is used to analyse as well as predict.