cd4 cd-wo • cd4 cell · · · Info · Definitions · Synonyms · Characters · · cd4 · · Text Common · · Latin · · Scripts 3 · · Length 1 · · Syllables Definitions · · · (noun) a glycoprotein that is found primarily on the surface of helper T cells. Synonyms: cluster of differentiation 4, CD4. Example: "Cd4 is a receptor for hiv in humans." · · Noun Definition 1 Synonyms · · · cluster of differentiation 4 · · Synonym 1 Characters · · 4 digit four U+0034 c latin small letter c U+0063 d latin small letter d U+0064