Etymology of fellatio by etymonline

fellatio fellatio n a form of sexual activity between two persons in which the penis of one is stimulated by the other's mouth, especially until orgasm is achieved

where the deceased was studying, the first accused indulged in acts of fellatio whereby he forced the deceased to indulge in unnatural oral sex with fellatio Fellatio also known as fellation, and colloquially as blowjob, BJ, giving head, or sucking off is an oral sex act involving the use of the mouth