(euphemistic) Scatological or vulgar language intended to be amusing.

Turned so that the back is now at the front.

Reversed, with the back now at the front.

(idiomatic) A much more pressing issue to attend to. / (idiomatic) A higher-valued result or target to reach.

Matching each member of one set with exactly one member of another set. / (chiefly UK) Involving direct communication between two people.

A personal relationship between two people.

(idiomatic) Required to, ought to, expected to / (idiomatic, with not) Permitted to.

back and forth; with a reciprocating motion.

To go back and forth; to alternate.

(dated) Pertaining to something or someone moving forward and back to the same position.