'hyaloclastic' originates from Greek elements via New Latin/modern geological usage: Greek 'hyalos' meaning 'glass' + Greek 'klastos' meaning 'broken', combined with the adjectival suffix '-ic'.

'hyaloclastic' formed in modern geological vocabulary from the noun 'hyaloclastite' (New Latin), itself from Greek 'hyalos' + 'klastos'; the adjective was created by adding '-ic' to describe materials or processes related to hyaloclastite.

Initially based on the literal components meaning 'glass-broken', it came to denote specifically the fragmentation of volcanic glass and deposits composed of such fragments in volcanology.