From Latin 'pietas' (piety), originally a charitable food donation to monks — the shrinking of the gifts shrank the word's meaning too.
A very small or inadequate amount of money or food.
From Old French 'pitance' (food allowed a monk, charitable donation), from Medieval Latin 'pietantia' (a pious donation), from Latin 'pietas' (piety, devotion). Originally a generous act of religious charity — extra food given to monks on feast days. The meaning reversed from 'charitable gift