The unofficial bastardized Latin motto of many organizations, particularly military units. "Semper", of course is the Latin word for "always". "Gumbi" refers to Gumby, a TV character made of clay. Thus, Semper Gumbi is translated as "Always Flexible."
G.I. Joe: "We were supposed to go back home a month ago but these Iraqis can't get their stuff together. Now we have to stay indefinitely."
G.I. Jack: "There's no use crying about it. Just suck it up and remember - Semper Gumbi."
Phenomenon created when some idiot with a loud car stereo believes the entire community would like to have their own music, conversations, or inner peace drowned out by the cacophony created by some angry black man shouting about bitches, a sampled bassline, and the sound of a car being vibrated apart.
Our day at the park was ruined by second-hand rap.