Rarefied***
(adj) refined
Recalcitrant***
(adj) resisting authority or control
Recant***
(v) to retract a statement or opinion
Recondite***
(adj) abstruse; profound
Refractory***
(adj) stubborn; unmanageable; resisting ordinary methods of treatment
Refute***
(v) to contradict; disprove
Relegate***
(v) to consign to an inferior position
Reproach***
(v) to find fault with; blame
Reprobate***
(n) morally unprincipled person
Repudiate***
(v) to reject as having no authority
Rescind***
(v) to cancel
Resolution***
(n) determination; resolve
Resolve***
(n) determination; firmness of purpose
Reticent***
(adj) not speaking freely; reserved; reluctant