Header image of wall of bricks Open menu Close menu


Also ‑acal.

Forming adjectives and nouns.

Latin ‑acus or French ‑aque from Greek ‑akos.

All words ending in ‑ac from this source include an i from the original Latin or Greek root, so making it in effect ‑iac.

Some are adjectives: cardiac (Greek kardia, heart), of the heart; iliac (Latin ilia, entrails), relating to the ilium, a bone in the pelvis, or to the nearby regions of the lower body. Others are nouns: aphrodisiac, a food, drink, or drug that stimulates sexual desire; zodiac, the belt of the heavens that includes the apparent paths of the sun, moon, and principal planets. Some can be both noun and adjective: amnesiac, hypochondriac, insomniac.

Nouns often have linked adjectives in ‑al (see ‑al1), as in zodiacal and ammoniacal. In a few cases, adjectives in both forms co-exist, as with paradisiac and paradisiacal, or heliac and heliacal (though in both these cases the form in ‑acal is much more common).

Some words in ‑ac have related forms in ‑ic: demoniac and demonic, haemophiliac and haemophilic, maniac and manic. In each of these cases the form in ‑ic is an adjective, irrespective of the role of the form in ‑ac. An exception is amnesiac, in which amnesic can be both adjective and noun.

Copyright © Michael Quinion 2008–. All rights reserved. Your comments are very welcome.