Related Clues:
- Like liquid nitrogen
- Without oomph
- Unable to react, as helium
- Like 103-Down
- Chemically nonreactive
- Phlegmatic
- Couchbound, perhaps
- Utterly lethargic
- Chemically quiet
- Hard to get a reaction out of
- Unable to react chemically
- Hard to combine, chemically
- Nonreactive, as some gases
- Like dead weight
- Nonreactive, chemically