ac-

From Old English āc (“oak”) (but not part of the etymology of acorn).

ac-

1. (in place names) oak.

• Around 1500 the c was added to some versions of the a- prefix.
• From Middle English a-, from Old French a-, from Latin ad- (“to, toward”).

• (Received Pronunciation) IPA^(key): /æk/, /ək/
• (US) IPA^(key): /æk/, /ək/

ac-

1. to or with.

   ‎ac- + ‎company → ‎accompany

   ‎ac- + ‎knowledge → ‎acknowledge

• ca, CA, C.A., ca., &ca., &ca

ac-

1. Alternative form of ad-

   Occurs when ad- is prefixed to a word beginning with the letter c or q (accēdō, acceptō, accessiō, acquiēscō, etc.)