S: (n) obstacle, obstruction (something immaterial that stands in the way and must be circumvented or surmounted) "lack of imagination is an obstacle to one's advancement"; "the poverty of a district is an obstacle to good education"; "the filibuster was a major obstruction to the success of their plan"
S: (n) rub, wipe (the act of rubbing or wiping) "he gave the hood a quick rub"
Verb
S: (v) rub (move over something with pressure) "rub my hands"; "rub oil into her skin"