'hypercellular' originates from Greek and Latin elements: the Greek prefix 'hyper-' meaning 'over, excessive' combined with Latin-derived 'cellular' from 'cellula' meaning 'small room' (a diminutive of Latin 'cella').

'hyper-' (Greek) + 'cellular' (from Latin 'cellula' → Medieval/Modern Latin 'cellularis' → English 'cellular') combined in medical/technical usage to form 'hypercellular' in modern English.

Initially the components conveyed 'over' + 'pertaining to small compartments (cells)', and over time the compound came to mean specifically 'having an excessive number of biological cells' in medical contexts.