I agree with Spitoon. "Avoiding action" implies that separation is lost or is about to be lost, and the instruction given along with it may be necessary to prevent a collision.
"Weather avoidance" is a pretty good term to use, depending on the standard of English of the pilot in question. I usually give try to give own navigation rather than a specified heading to get around weather, unless separation demands otherwise or the pilot has suggested the heading he/she needs. Then I'll say "report when able to accept vectors" or "report when able to accept a [direction] turn" and this seems to keep most people happy.