Rare :: Rare (superl.) Characterized by wide separation of parts; of loose texture; not thick or dense; thin; as, a rare atmosphere at high elevations..
Rarebit :: Rarebit (n.) A dainty morsel; a Welsh rabbit. See Welsh rabbit, under Rabbit..
Raree-show :: Raree-show (n.) A show carried about in a box; a peep show.
Rarefaction :: Rarefaction (n.) The act or process of rarefying; the state of being rarefied; -- opposed to condensation; as, the rarefaction of air..
Rarefiable :: Rarefiable (a.) Capable of being rarefied.
Rarefy :: Rarefy (v. t.) To make rare, thin, porous, or less dense; to expand or enlarge without adding any new portion of matter to; -- opposed to condense..
Rarefy :: Rarefy (v. i.) To become less dense; to become thin and porous.