There are four origins of this idiom (I GUARANTEE IT):
- English archers protected their bows by putting the strings on their heads under their helmets;
- βkeep it under our hatβ was mentioned in 1982 in periodical "Gleanings in Bee Culture";
- President Abraham Lincoln's stove pipe hat, where he kept important papers;
- the ceremonial swordbearer of the Lord Mayor of London (can be dated to 1420), who keeps the key to the Lord Mayorβs seal of office in a special pocket in his hat.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.