そのナイフは血にまみれていた。

that (something or someone distant from the speaker, close to the listener; actions of the listener, or ideas expressed or understood by the listener); the; um...; er...; uh...

knife

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

blood; consanguinity

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

to be smeared; to be covered