Colloquialism for the selector lever on a select-fire firearm or
safety on an automatic weapon, which engages the mechanical safety,
semi-automatic fire, or automatic fire/3 round burst. Switching to automatic fire and putting streams of lead downrange is well known to elicit giggles of joy from anyone who grew up playing
video games or watching GI Joe/The A-Team.
1) Private Joe Snuffy
flipped the
giggle switch on his M-249 for the first
time, and laughed maniacally as he engaged the pop-up targets on his qualification range.
2) Rangemaster: "Flip that giggle switch and give 'er a whirl
Trainee: "heh heh heh . . ." *BRRRRRRRRAP!*