I. “+ noun
Etymology: in- (I) + variant
: a constant factor : one that does not change ; specifically : a mathematical expression or magnitude that remains unchanged under prescribed or implied conditions
II. adjective
Etymology: in- (I) + variant
1. : constant , unchanging , unvarying , universal
16 subjects were presented, on 4 successive days, with 300 invariant stimuli — Biological Abstracts
basic human emotions … are invariant — H.B.Parkes
specifically : unaffected by the group of mathematical operations under consideration
2. : having no degree of freedom — used of a physical-chemical system; compare phase rule