complete denial of knowing (an incident in question)

to know through one's own experience

to have no way of knowing; to be completely ignorant of

to make known

(Classical Japanese, archaic, honorific) to know

God only knows

Watch yourself, be careful, literally, "keep your health" / take care (used when parting)

police dog

attach, affix, stick, fasten, add, add on, append; set, put, put one thing on another / apply, put on / leave a mark on / write, make an entry / give, impart, direct, direct one's attention

(meteorology) psychrometer