Related Clues:

• Turns into compost
• Starts to stink, say
• Sours
• Goes bad, as fruit
• Turns bad
• Languishes: slang
• Goes to the dogs
• Turns to compost
• Goes to hell
• Turns in the fridge
• Languishes in the lockup
• Addles
• Gets inedible
• Gets smelly, say
• Turns, in a sense