No English words meet the criteria. Here are all the opitons that contain RAH:
3-letter words
rah
5-letter words
gerah, horah, prahu, surah, Torah
6-letter words
brahma, coprah, dourah, gerahs, graham, hoorah, horahs, hurrah, jarrah, prahus, sirrah, surahs, torahs
7-letter words
begorah, brahmas, coprahs, dourahs, grahams, hoorahs, hurrahs, jarrahs, menorah, sirrahs
8-letter words
begorrah, copperah, haftarah, haftorah, hoorahed, hurrahed, menorahs, ultrahot
9-letter words
copperahs, haftarahs, haftorahs, hoorahing, hurrahing, ultraheat, ultrahigh, vibraharp
10-letter words
infrahuman, satyagraha, subtrahend, tetrahedra, ultraheats, ultraheavy, ultrahuman, vibraharps
11-letter words
infrahumans, satyagrahas, subtrahends, tetrahedral, tetrahedron, tetrahymena, ultraheated
12-letter words
extrahepatic, tetrahedrite, tetrahedrons, tetrahymenas, ultraheating, vibraharpist
13-letter words
tetrahedrally, tetrahedrites, vibraharpists
14-letter words
bremsstrahlung, ultrahazardous
15-letter words
bremsstrahlungs, tetrahydrofuran
16-letter words
tetrahydrofurans
20-letter words
tetrahydrocannabinol
21-letter words
tetrahydrocannabinols
76 words