hansolorgasm:

BB-8’s name was chosen by Episode VII director J.J. Abrams because of the droid’s round and bouncy look. Abrams is also quoted
with saying, “I named him BB-8 because it was almost onomatopoeia. It
was sort of how he looked to me, with the 8, obviously, and then the two
B’s.” The name was conceived early on in Episode VII’s production and
was one of the few to never be changed. (x)