R / rārēfăcĭo
verb transitive

rārēfăcĭo

2nd PP rārē-făcere · 3rd PP rārēfēci · 4th PP rārēfactum · conj. 3rd-io
(written also separately ), rarus
to make thin; rare; to rarefy
to make thin or rare, to rarefy (Lucret.): rarefieri, Lucr. 1, 648: rarefacta, id. 2, 1139; 3, 442: rareque facit, id. 6, 233; 870.