"Window" captures some of the meaning you're trying to express; in the sense of a gap between solid things, as well as something moving and only available for a certain period of time, as a "launch window."

What is the exact word used for this unusual "interval" of sorts?
According to the Cold[EX] ability of an Ice Golem


  An ice golem's body generates intense cold, dealing 1d6 points of damage with its touch. 


If a Golem were to initiate a grapple, would this ability trigger dealing damage to grappled target?

If so, would this be on the Golem's turn, on the target's turn, or on both turns?
