frugal adj.

*bhrūg-, Proto-Indo-European root meaning "to enjoy," with derivatives referring to agricultural products.

It forms all or part of: brook (v.) "to endure;" defunct; fructify; fructose; frugal; fruit; fruitcake; fruitful; fruition; fruitless; frumentaceous; function; fungible; perfunctory; tutti-frutti; usufruct.

It is the hypothetical source of/evidence for its existence is provided by: Latin frui "to use, enjoy," fructus "an enjoyment, proceeds, fruit, crops;" Old English brucan "use, enjoy, possess," German brauchen "to use."

1530s, "economy, thriftiness," from French frugalité (14c.), from Latin frugalitatem (nominative frugalitas) "thriftiness, temperance, frugality," from frugalis (see frugal).

FRUGALITY. The disposition to save or spare what we have got, without any desire to gain more. It is constantly, of course, associated with avarice ; but quite as frequently with generosity, and is often merely an extreme degree of housewifely habit. [Ruskin, "Fors Clavigera"]

"feeding on fruits," 1833, from Latin frugi-, stem of frux "fruit, produce" (see frugal) + -vorous "eating, devouring."