Word.ws English Dictionary

ac-

UK/æk/US/æk/

ac- prefix: oak.

Prefix (1)

ac-

  1. oak.
    • Acton

Prefix (2)

ac-

  1. To or with.
    • ac- + company → accompany

Prefix (3)

ac-

  1. On.
    • ac- + knowledge → acknowledge

Origin of ac-

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

Assimilated form of ad- before c, k, q. 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”).

Assimilated form of a-. Around 1500 the c was added to some versions of the a- prefix. From a- (“on”), from Old English ge-.

Questions about ac-

What does ac- mean?
Ac- means oak.
What part of speech is ac-?
Ac- is a prefix.
How do you pronounce ac-?
Ac- is pronounced /æk/ (UK).

Words near ac- in the dictionary

  1. AC adapter
  2. AC adapters
  3. ac etiam
  4. AC Plonk
  5. AC Plonks
  6. ac-
  7. ac.
  8. AC/DC
  9. AC45
  10. AC45's
  11. AC45s

Source and license

Adapted from Wiktionary: ac- (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “ac-.” Word.ws, https://word.ws/ac-. Based on Wiktionary, CC BY-SA 4.0.