friction; rubbing; chafing; discord; friction
fricative; fricative consonant
frictional resistance; frictional drag; frictional force
sibilant; sibilant consonant
rubdown with a wet towel; cold-water rubbing
rubbing an ointment into the skin
frictional electricity; triboelectricity
bowed stringed instrument
brush-mark pattern (scraped into the surface of earthenware with wood)
angle of friction; frictional angle
liniment; ointment; salve