She wants to restore an old theater that is 'falling into decay'. [=falling into ruin]
We're concerned about the 'decay' [='deterioration'] of our public school system.
Tomatoes that fall off the vine will 'decay' [='rot'] on the ground.
(..) - Pulse , regular. Okay, this may be a little uncomfortable. It's got a little zap to it, doesn't it? He just implanted a radium diode. Don't worry, it's safe. The isotope decays predictably. As a result, these numbers change over time. They're the access codes to your drop spot. (..)2001 A Beautiful Mind