Latin. According to the rate; in proportion. If a lawyer charges $100 per hour, and she works a quarter of an hour, her pro rata fee would be $100/4, or $25. pro se adj/adv. Latin. For himself; on one's own behalf; on one's own. Characterization of one who represents himself/herself in an action without the assistance of an attorney at law and who acts as his/her own attorney of record