A boonie hat or booney hat, also called giggle hat, is a kind of wide-brim hat commonly utilized by military forces in hot tropical climates. Its design is comparable to a bucket hat but with a stiffer brim. Ordinarily a fabric tape band of 'branch loops' is usually sewn around the crown of the hat. This 'foliage ring' is intended to carry additional vegetation as camouflage. A strap provides stability. The crown could be vented with eyelets or small mesh panels. Snaps can also be provided with which to repair the brim in the design of an Australian bush hat.
Source: military headwear
U.S. military Boonie hat
A blue cap with an throughout brim was issued within the 1937 blue denim fatigue uniform that was nicknamed the "Daisy Mae hat". The M1941 green herringbone twill cloth fatigue uniform featured the same hat. The military caps influenced "Johnny Jeep" hats (or "Johnny Jeepers") that have been featured on the cover of the August 24, 1942 cover of LIFE magazine and mocked in the accompanying article. The cover features two female models wearing the hats however you like, as the article notes that the style accessory cost $25 at John-Frederic's (from famous milliner referred to as Mr. John) and the "Army hat" costs 45¢. Photos of GIs demonstrating other ways to wear the hat are contained in the tongue-in-cheek article. Lord & Taylor produced licensed copies for a lower life expectancy price; cheap knockoffs ("bootleg imitations") soon followed.
The boonie hat was introduced to america Armed Forces through the Vietnam War, when U.S. Army Green Berets began wearing them in the field, along with Australian and Army of the Republic of Vietnam units. These leopard spot or tigerstripe boonie hats were locally procured, and the camouflage cloth was usually salvaged from other uniform items, parachutes, or fabricated by a tailor. The name comes from "boonie", the abbreviated type of boondocks (itself originally American military slang produced from Tagalog bundok, "mountain", through the Philippine-American War). The hat was like the hat worn with the pattern 1941 HBT fatigue uniform.
In 1967, the U.S. Army began issuing boonie hats, as the "Hat, Jungle, with Insect Net", manufactured from cotton and wind-resistant poplin, in olive drab, tigerstripe, and ERDL pattern. It had been designed to supplement and replace the patrol and baseball caps that were operating since World War II. As the U.S. military evolved from a garrison mentality, the boonie hat found a permanent place within the uniform of most services. The boonie hat offers changed little through the decades because the Vietnam War and was found in the Iraq War but still in the War in Afghanistan instead of the patrol cap. The U.S. military boonie hat provides come in a number of camouflage patterns; the existing assortment includes Woodland, three-color desert, UCP, MultiCam, and both desert and woodland versions of MARPAT, along with the Air Force ABU pattern. The boonie hat is often worn with the wearer's rank insignia pinned or sewn to leading, above the branch loops.