| acoraceae | (n) used in some classifications for the genus Acorus which is usually assigned to Araceae, Syn. subfamily Acoraceae |
| acorea | (n) absence of the pupil in an eye |
| acorn | (n) fruit of the oak tree: a smooth thin-walled nut in a woody cup-shaped base |
| acorn barnacle | (n) barnacle that attaches to rocks especially in intertidal zones, Syn. rock barnacle, Balanus balanoides |
| acorn-shaped | (adj) shaped like an acorn |
| acorn squash | (n) squash plant bearing small acorn-shaped fruits having yellow flesh and dark green or yellow rind with longitudinal ridges |
| acorn squash | (n) small dark green or yellow ribbed squash with yellow to orange flesh |
| acorn tube | (n) a small vacuum tube; used at high frequencies |
| acorus | (n) sweet flags; sometimes placed in subfamily Acoraceae, Syn. genus Acorus |
| Acorn | n. [ AS. æcern, fr. æcer field, acre; akin to D. aker acorn, Ger. ecker, Icel. akarn, Dan. agern, Goth. akran fruit, akrs field; -- orig. fruit of the field. See Acre. ] |
| Acorn cup | The involucre or cup in which the acorn is fixed. [ 1913 Webster ] |
| Acorned | a. |
| Acorn-shell | n. (Zool.) One of the sessile cirripeds; a barnacle of the genus |