Grot"to (?), n.; pl. Grottoes (#). [Formerly grotta, fr. It. grotta, LL. grupta, fr. L. crypta a con cealed subterranran passage vault, cavern, Gr. , fr. concealed, fr. to conceal. Cf. Grot, Crypt.]
A natural covered opening in the earth; a cave; also, an artificial recess, cave, or cavernlike apartment.
© Webster 1913.