The precursor to the term "blow job". some time in the past people would refer to the act as a "below job" since it was done "down there". When spoken quickly it often sounds like blowjob thus creating that term.
Hey Johnny, I had a swell time last night! Why don't we hop in your Edsel and I give you a below job.
by A. Roy August 10, 2006
Eric got a blowjob from one of his 14 years old friends, and proudly told Sindre and Hermann: "I got a belowjob yesterday!"
by CarlAndre July 13, 2012