Source : Webster's Revised Unabridged Dictionary (1913)

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.

Thatch \Thatch\, n. [OE. thak, AS. [thorn][ae]c a roof; akin to
   [thorn]eccean to cover, D. dak a roof, dekken to cover, G.
   dach a roof, decken 8cover, Icel. [thorn]ak a roof, Sw. tak,
   Dan. tag, Lith. st[=o]gas, Ir. teagh a house, Gael. teach,
   tigh, W. ty, L. tegere to cover, toga a toga, Gr. ?, ?, a
   roof, ? to cover, Skr. sthag. Cf. {Deck}, {Integument},
   {Tile}, {Toga}.]
   1. Straw, rushes, or the like, used for making or covering
      the roofs of buildings, or of stacks of hay or grain.

   2. (Bot.) A name in the West Indies for several kinds of
      palm, the leaves of which are used for thatching.

   {Thatch sparrow}, the house sparrow. [Prov. Eng.]

Source : WordNet®

thatch
     v : cover with thatch; "thatch the roofs"

thatch
     n 1: hair resembling thatched roofing material
     2: plant stalks used as roofing material
     3: an English pirate who operated in the Caribbean and off the
        Atlantic coast of North America (died in 1718) [syn: {Teach},
         {Edward Teach}, {Edward Thatch}, {Blackbeard}]
     4: a house roof made with a plant material (as straw) [syn: {thatched
        roof}]