'lymphocyte-dominant' is a compound of 'lymphocyte' and 'dominant'. 'lymphocyte' originates in Neo-Latin/Greek elements: Greek 'lympha'/'lymph-' (via Latin 'lympha') meaning 'water' (used for the lymphatic fluid) and Greek 'kytos' meaning 'container, cell' (forming '-cyte'). 'dominant' originates from Latin 'dominans' (present participle of 'dominare'), related to 'dominus' meaning 'master or lord'.

'lymphocyte' entered English in scientific usage via Neo-Latin and modern coinage from Greek roots ('lymph-' + '-cyte'); 'dominant' passed into English from Old French and Latin 'dominans' and came to be used in English from Middle English onwards; the hyphenated compound 'lymphocyte-dominant' arose in modern medical English to describe cellular predominance.

Initially the parts meant 'lymph-related cell' and 'ruling/master'; combined in modern medical usage they evolved to mean 'having a predominance of lymphocytes' rather than any literal sense of 'ruling'.