mid-14c., "table where a money lender does business," from Old French contouer, comptoir "counting room; table or bench of a merchant or bank" (14c.), from Medieval Latin computatorium "place of accounts," from Latin computatus, past participle of computare "to count, sum up, reckon together" (see compute).
Generalized 19c. from banks to shops, then extended to display cases for goods. In reference to a similar construction in a home kitchen by 1875. Over the counter in reference to goods sold and money paid is by 1875; phrase under the counter in reference to illegal or clandestine transactions is by 1926.
"go against, come against, engage in combat," late 14c., short for acountren, encountren (see encounter (v.)). In boxing, "to give a return blow while receiving or parrying a blow from one's opponent," by 1861. Related: Countered; countering.
c. 1300, countour, "one who counts or reckons, an accountant, a local tax official," from Anglo-French countour, which is from an Old French merger of Latin computator and Medieval Latin computatorium, both ultimately from Latin computare "to count, sum up, reckon together" (see compute).
From late 14c. as "metal disk or other thing used in counting." From 1803 as "apparatus for keeping count."
1590s, "acting in opposition," from counter (adv.) or counter-. From 1823 as "duplicate."