Button to disable delay but leave effect trail?

Good day! Recently introduced to MS3 and I'm loving it thus far. I have a quick question. I have a button mapped to "Bypass" the delay that I'm using on a voice channel to trigger it off and on. Obviously, the Bypass kills the delay signal. What I'm after is how to simply disable the "input" to the effect but leave the trail playing.

Think of the vocal part in Pink Floyd's "Us & Them", for example. I'd like to be able to trigger the delay for a word, then disable the effect while singing the rest of the line, but have the effect trail off without bypassing it. What is the parameter I'd need to adjust to accomplish this?

I'm not having much luck figuring it out - probably a brain fart on being overwhelmed by the majesty of the software, haha.

Thanks in advance for any assistance!