'cellular-rich' is a modern English compound formed from 'cellular' and 'rich'. 'Cellular' ultimately comes from Latin 'cellula' (a diminutive of 'cella'), meaning 'small room' or 'little chamber', while 'rich' comes from Old English 'rice' (from Proto-Germanic *rīkaz) meaning 'powerful' or 'wealthy', later shifting to 'abundant'.

'cellula' (Latin) → Medieval/Modern Latin 'cellula' → English adjective 'cellular'; Old English 'rice' → Middle English 'rich' → Modern English 'rich'. The compound 'cellular-rich' arises in Modern English usage by joining these two adjectives to describe abundance of cells.

Originally 'cellula' referred to a 'small room' and 'cellular' to things relating to small compartments; 'rich' originally meant 'powerful/wealthy' and shifted toward 'abundant'. Together the compound evolved to mean 'abundant in cells' in biological contexts.