A hand job, also spelled handjob, is a form of manual stimulation performed on a penis. It may be used as foreplay or may be continued to the point of orgasm and ejaculation. It involves many techniques, which differ depending on partner preferences and may or may not include stimulation of the testicles, scrotum and perineum along with the penis.
According to Merriam Webster, the first known use of the term hand job in this context was in 1939.
A hand job is occasionally called hand sex or handsex.