name of the Greek and Roman conception of the Egyptian sovereign sun-god Amun (said to mean literally "hidden"), also Amen-Ra. This they confused with the ram-headed divinity, god of life, worshipped at an oracular sanctuary in Libya. See ammonia. Related: Ammonian.

late 14c., ammoniak, also armonyak, in reference to certain gums, earths or salts (sal ammoniac) used medicinally and held to have similar properties (see ammonia); from Old French ammoniac, armoniac, ultimately from Greek *ammoniakos, from the god-name Ammon (q.v.).

The gum (Latin guttae ammoniaci) came from a wild plant that grew across North Africa and Asia. The earth (Latin bolus armenicus) was so called because the substance was found in Armenia; hence the medieval forms were confused with words from Greek harmonia (gum ammoniac was used as a binding agent) or Armenia.

also amide, in chemical use, 1850, word-forming element denoting a compound obtained by replacing one hydrogen atom in ammonia with an element or radical, from French amide, from ammonia + -ide.

"compound in which one of the hydrogen atoms of ammonia is replaced by a hydrocarbon radical," 1863, from ammonia + chemical suffix -ine (2).

name for salt formerly much used in pharmacy and old chemistry, late 14c., from Old French sal, from Latin sal (genitive salis) "salt" (from PIE root *sal- "salt"). For sal ammoniac "ammonium chloride" (early 14c.), see ammonia. Sal volatile, "ammonium carbonate," especially as used in reviving persons who have fainted, is by 1650s, Modern Latin, literally "volatile salt" (see volatile).