Sabaki is a generic name for some techniques required for high-level light play - but doesn't mean light play (as often asserted).
The opposite of light play is heavy play.
The concept of playing lightly is usually talked about in terms of defence. It also matters when you are attacking, though: because the attacker should be flexible and (in general) avoid over-commitment, as well. See for example the two different kinds of example cited at screening kikashi.
Tamsin Just a quick thought here: I was studying a game of O Rissei's in which he played in his opponent's sphere of influence, surprisingly close to his thickness. O made several moves, but not a single solid connection. It's not very profitable to capture a single stone in gote, but neither is it easy to attack numerous stones that are only loosely connected.