Related Clues:
- Hard to get a reaction out of
- Unable to react chemically
- In need of an update
- Hard to combine, chemically
- Nonreactive, as some gases
- No longer interesting
- Like old pretzels
- Well past the sell-by date
- Like dead weight
- Nonreactive, chemically
- Like a dead weight
- Like days-old bread
- Like many a crossword clue for the word OREO, or like old Oreos
- Unfresh
- Hard to get a reaction out of?