purchaser n.

c. 1300, purchasen, "acquire, obtain; get, receive; procure, provide," also "accomplish or bring about; instigate; cause, contrive, plot; recruit, hire," from Anglo-French purchaser "go after," Old French porchacier "search for, procure; purchase; aim at, strive for, pursue eagerly" (11c., Modern French pourchasser), from pur- "forth" (possibly used here as an intensive prefix; see pur-) + Old French chacier "to run after, hunt, chase" (see chase (v.)).

Originally to obtain or receive as due in any way, including through merit or suffering; the specific sense of "acquire or secure by expenditure of money or its equivalent, pay money for, buy" is attested from mid-14c., though the word continued to be used for "to get by conquest in war, obtain as booty" up to 17c. Related: Purchased; purchasing.