English

isosyllabic

From iso- + syllabic.

Ancient Greek ἴσος ‘equal’

English iso-

Proto-Indo-European *(s)leh₂gʷ- ‘to take, grasp’

…

Ancient Greek σῠλλᾰμβᾰ́νω ‘to bring together’

Ancient Greek συλλαβή ‘syllable’

Ancient Greek συλλαβικός

Medieval Latin syllabicus

Today it means

adj of or pertaining to metrical systems in which syllables are of equal length

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

Etymograph / isosyllabic