n.
Pronunciation: ˌ de-k ə -m ə - ' th ō -n ē - ə m
Function: noun
Etymology: deca- + meth ylene + -onium
Date: circa 1949
: a synthetic ion used in the form of either its bromide or iodide salts (C 16 H 38 Br 2 N 2 or C 16 H 38 I 2 N 2 ) as a skeletal muscle relaxant also : either of these salts