(humorous) To watch something that has virtually no movement, hence, something very boring.

(transitive, simile) To observe (someone or something) closely and keenly.

A woodboring beetle, namely a beetle whose larvae are xylophagous.

(idiomatic, US) To be careful about what one says, especially with regard to disrespectful or profane language.

plural of death-watch beetle

(idiomatic) to pay careful attention to a situation or a thing, so that you can deal with any changes or problems.

To move cautiously. / (idiomatic) To be cautious.

(UK) To pause and remain still whilst doing nothing but surveying the environment around oneself.

Alternative form of watch one's mouth

Indicating concern as to whether those responsible for monitoring the behavior of others are themselves held accountable.