(a) seated as on a sofa; (b) furnished with a sofa or sofas.

Of an object: placed on a table. Of a person: seated at a table.

Seated in an armchair. Occasionally also (and in earliest use): lacking or not involving practical or direct experience (= armchair, adj.).

Seated or placed on a bench; spec. North American Sport (of a player) removed from a game or prevented from taking part in it; (hence) removed from…