Main Entry: ac·cus·tom

Pronunciation: \ə-ˈkəs-təm\

Function: transitive verb

Etymology: Middle English, from Anglo-French acostomer, from a- (from Latin ad-) + custume custom

Date: 15th century

: to make familiar with something through use or experience

— ac·cus·tom·ation \-ˌkəs-tə-ˈmā-shən\ noun