English

triblock

From tri- + block.

A compound of tri- + block

Proto-Indo-European *tri- ‘three, threefold’

Proto-Italic *tri- ‘three, tri-’

English tri-

Proto-Indo-European *bʰelǵ- ‘thick plank’

…

Old Dutch *blok ‘log’

Middle Dutch blok ‘treetrunk’

Old French bloc ‘log’

Middle English blok ‘log’

English block

Today it means

noun A block copolymer that has three distinct blocks

Language periods are conventional ranges, not dates for this word.

Etymograph / triblock