n. 25B6; verb
they interchange ideas : EXCHANGE, trade, swap, barter, bandy, reciprocate; archaic truck.
the terms are often interchanged : SUBSTITUTE, transpose, exchange, switch, swap (round), change (round), reverse, invert, replace.
25B6; noun
the interchange of ideas : EXCHANGE, trade, swap, barter, give and take, traffic, reciprocation, reciprocity; archaic truck.
a motorway interchange : JUNCTION, intersection, crossing; N. Amer. cloverleaf.