n. The early form of oak, preserved (through the shortening of the vowel before two consonants) in certain place-names (whence surnames): as, Acton [⟨ AS. Āctū n], literally, oak-town, or dwelling among the oaks: Acley or Ackley, also Oakley [⟨ AS. Ācleá], literally, oak-lea.n. A prefix, assimilated form of ad- before c and q, as in accede, acquire, etc.; also an accommodated form of other prefixes, as in accurse, accloy, accumber, etc. See these words.n. An adjective-suffix of Greek or Latin origin, as in cardiac, maniac, iliac, etc. It is always preceded by -i- and, like -ic, may take the additional suffix -al.etc. Points of flexure in the heating curves of iron and steel. The point ac1 on heating is the same as ar1 on cooling, etc.