foolproof (v.)
- bombproof
- bulletproof
- certain
- fireproof
- handy
- proof
- safe
- soundproof
- sure
- tight
- weatherproof
foolproof (adj.)
- adaptable
- airtight
- bombproof
- bulletproof
- burglarproof
- certain
- convenient
- dependable
- ductile
- feasible
- fire-resisting
- fireproof
- flameproof
- flexible
- guaranteed
- handy
- hermetic
- infallible
- leakproof
- malleable
- manageable
- maneuverable
- pliable
- pliant
- practical
- proof
- reliable
- resistant
- rustproof
- safe
- shatterproof
- shellproof
- soundproof
- sure
- sure-fire
- tight
- tractable
- trustworthy
- unfailing
- warranted
- watertight
- weatherproof
- wieldy
- yielding
