1540s, justle, "to knock against" (transitive), formed from jousten "to joust, tilt, fight in single combat" (see joust (v.)) + frequentative suffix -le (see -el (3)). According to OED, the usual spelling 17c.-18c. was justle. An earlier meaning of the word was "to have sex with" (c. 1400). Meaning "contend for the best position or place" is from 1610s. Related: Jostled; jostling. As a noun from c. 1600.