What does irrūgo mean in Latin?

irrūgo, a verb, means “to wrinkle”.

verb

irrūgo

irrūgo (inr-), āre, v. a. in-rugo,

I. to wrinkle, make wrinkled.

I. Lit.: aequor ventris, Gell. 12, 1, 8.—

II. Transf., to fold: sinum, Stat. Th. 4, 266.