A lot vs. Alot: 9 Grammatical Pitfalls
1620s, "wrinkled" (of skin, etc.), past participle adjective from corrugate. Meaning "bent into curves or folds" (of iron, cardboard, etc., for elasticity and strength) is from 1853.
1620s; implied earlier as a past participle adjective (early 15c.), from Latin corrugatus, past participle of corrugare "to wrinkle very much," from com-, intensive prefix (see com-), + rugare "to wrinkle," of unknown origin.