- v lessen the density or solidity of
- v make more subtle or refined
- v weaken the consistency of (a chemical substance)
- Before the contest was over they had done it three times more, belatedly accepting knarled (for gnarled), coruscate with a double "r" and rarefy with an "i," after first waving the .
- It contains moist air and a movable diaphragm or piston to rarefy it suddenly.