Joab Eichenberg-Eilon (asker) Jul 31, 2011:

Must be a formal term with tax implications Thanks for the attempts so far. Usufruct has to do with enjoyment of another person's asset (like the fruit of someone else's tree). Yielding and fruitful are obvious, but they don't have the formal distinction of הכנסה פירותית from, for example, הכנסה הונית, in terms of their different tax status.

meirs Jul 31, 2011:

most probably derives from the "fruct" part of usufruct.