Quack
charlatan; fake
Quaff
drink down quickly
Quagmire
marsh; bog
Quaint
odd; old-fashioned; picturesque
Qualm
hesitation or fear
Quandary
dilemma; puzzle
Quarantine
isolation to prevent the spread of disease
Quarry
Quell
suppress
Querulous
always complaining
Quibble
Quintessential
most typical; the perfect example of [quintessence(n)]
Quirk
oddity
Quisling
traitor
Quixotic
impractically idealistic
Quotidian
daily; routine
Raconteur
story-teller
Ramble
wander aimlessly
Ramifications
branches; subdivisions of a complex system; outcomes
Rancor
bitterness; hatred
Rant
use bombastic language
Rarefy
make less dense [rarefaction (n)]
Ratify
approve; consent
Raucous
rough and unpleasant (of sounds)