n. & v.
n. 1 a roof-covering of straw, reeds, palm-leaves, or similar material. 2 colloq. the hair of the head.
v.tr. (also absol.) cover (a roof or a building) with thatch. thatcher n.
[ n. late collateral form of thack (now dial.) f. OE thc, after v. f. OE theccan f. Gmc, assim. to thack ]