(transitive) To personally verify that (someone or something) is safe, copacetic, appropriate or satisfactory.

The act of checking in at a hotel, airport, etc. / (computing) The submission of source code or other material to a source control repository.

To announce or record one's own arrival at a hotel, airport etc. / To verify a person's information and record their arrival, such as at a hotel, airport, etc.

To inspect; to examine. / To verify the accuracy of a text or translation, usually making some corrections (proofread) or many (copyedit).

(heraldry) Divided into small squares (chequers) by transverse vertical and horizontal lines.

(textiles, usually pluralized) A pattern made up of a grid of squares of alternating colors; a checkered pattern. / Any fabric woven with such a pattern.

(chess) A situation in which the king is directly threatened by an opposing piece. [from 14th c.] / An inspection or examination. / A control; a limit or stop.

(transitive) To mark with a check pattern.

simple past tense and past participle of check in

(Canada, US) Having a pattern of checks; checkered. / (phonology) Of syllables, having a coda. / (phonology) Of consonants, glottalized. / Verified or validated in some way.