momentary

the word 'momentary' traces its lineage to the latin momentum, which originally denoted a physical 'movement' or 'motion'. this concrete sense evolved metaphorically to signify a 'brief, moving instant of time', as a moment is a point in time that swiftly moves past. the suffix -arius was added to form an adjective, a practice common in medieval latin. thus, the literal construction 'pertaining to a moving instant' evolved into the modern abstract meaning of something lasting for a very short time or occurring at any instant.

Structure: moment (a brief period of time) + ary (adjective-forming suffix) moment (from latin momentum, meaning 'movement, motion, short time, importance', from movere 'to move'); ary (from latin -arius, an adjectival suffix meaning 'pertaining to, connected with').