From The Collaborative International Dictionary of English v.0.48 [gcide]: Thatch \Thatch\, v. t. [imp. & p. p. Thatched; p. pr. & vb. n. Thatching.] [From Thatch, n.: cf. OE. thecchen, AS. ?eccean to cover.] To cover with, or with a roof of, straw, reeds, or some similar substance; as, to thatch a roof, a stable, or a stack of grain. [1913 Webster]