'subhedral' originates from Latin prefix 'sub-' meaning 'under, somewhat' combined with the combining form '-hedral' from Greek 'hedra' meaning 'seat' or 'face'.

'-hedral' derives from Greek 'hedra' (ἕδρα) meaning 'seat' or 'face'; the combining form '-hedral' was adopted into English scientific terminology (e.g. 'polyhedral', 'euhedral') and 'sub-' was prefixed by analogy to form 'subhedral' in mineralogical/crystallographic usage.

Initially the root referred to a 'seat' or 'base' (geometric face); over time the combined form came to describe the degree to which crystal faces are developed, yielding the current meaning 'partly having crystal faces'.