to insert, to put in (such that there is a snug fit), to button, to put on (something that envelops, e.g. gloves, ring). Usually written with kana alone.
to have sex, to fuck. Colloquialism.
to pigeonhole (into a particular category).
to place a ring-shaped object around something (esp. one that restricts freedom, such as handcuffs).
to entrap, to set someone up (e.g. frame them for a crime, etc.).