'low-cellularity' is a compound formed in modern English from 'low' + 'cellularity'. 'low' originated in Old English (from words such as 'hlēow'/'hlēowig') meaning 'not high' or 'situated below', while 'cellularity' derives from 'cell' (from Latin 'cella' meaning 'small room or storeroom') plus the nominal suffix '-ity' (from Latin '-itas').

'cell' entered English via Latin 'cella' and Middle English 'celle'; 'cellular' developed from 'cell' with the adjective-forming suffix '-ar', and 'cellularity' was formed later by adding the noun-forming suffix '-ity' to 'cellular'. The compound 'low-cellularity' is a descriptive modern English formation used especially in medical contexts.

Initially 'cell' referred to a small room; with the development of biological science it came to denote the basic structural unit of organisms. 'Cellularity' came to mean 'the quality or state of having cells', and in medical usage evolved to denote the density or abundance of cells in a sample; 'low-cellularity' therefore specifically denotes a reduced cell density.