on

Rub Rub, v. i. 1. To move along the surface of a body with pressure; to grate; as, a wheel rubs against the gatepost. [1913 Webster]

2. To fret; to chafe; as, to rub upon a sore. [1913 Webster]

3. To move or pass with difficulty; as, to rub through woods, as huntsmen; to rub through the world. [1913 Webster]

{To rub along} or {on}, to go on with difficulty; as, they manage, with strict economy, to rub along. [Colloq.] [1913 Webster]