is a specific kind of: headdress, headgear.

is a broader term that covers: bearskin, busby, shako | boater, leghorn, Panama, Panama hat, sailor, skimmer, straw hat | bonnet, poke bonnet | bowler, bowler hat, derby, derby hat, plug hat | campaign hat | cavalier hat, slouch hat | cocked hat | cowboy hat, ten-gallon hat | deerstalker | beaver, dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper | dunce's cap, dunce cap, fool's cap | fedora, felt hat, homburg, Stetson, trilby | fur hat | millinery, woman's hat | shovel hat | snap-brim hat | sombrero | sou'wester | sun hat, sunhat | titfer | toque | tirolean, tyrolean ... show more.

has as a part: brim | crown | hatband.

derivation: hatmaker, hatter, milliner, modiste | hat | hat.