The expression pro rata can mean proportional or proportionally.
e.g. Tim was paid on a pro rata basis
So the more Tim works, the more he is paid. Neat!
Abbreviated: a.m. & p.m., cf., e.g., et al., etc., i.e., N.B., P.S., Q.E.D., q.v., viz.
Non abbreviated: ad hoc, de facto, modus operandi, non sequitur, pro rata, quid pro quo, sic, vice versa.