From Latin "lingua" (tongue) and "Cunni" (cunts cunnus being the singular version), a cunnilingual is someone who is proficient at attaching his tongue to a pussy.
kuhn-l-ing-gwuhl - (1) adjective - a man who accepts oral stimulation of his penis by women, and who returns the favor by licking vagina.
(1) advice - Being cunnilingual greatly increases your chances of getting a blow job (2) contextual - "I'm not into the 69 thing, baby; I'm not cunnilingual".