Roost \Roost\, v. i. [imp. & p. p. {Roosted}; p. pr. & vb. n. {Roosting}.] 1. To sit, rest, or sleep, as fowls on a pole, limb of a tree, etc.; to perch. --Wordsworth. 2. Fig.; To lodge; to rest; to sleep. O, let me where thy roof my soul hath hid, O, let me roost and nestle there. --Herbert.