malavara

English has this backwards, and Esperanto will not let you forget it. In English, generous is the plain word and ungenerous is the awkward negation you reach for when you have to. Esperanto puts the plain word on the other side: avara is stingy, tight, avaricious, and malavara is that reversed. Being open-handed is the marked case, the not-mean one. It is worth sitting with rather than translating away, because it is the single most common reason a beginner reaches for a word that does not exist. There is no root generoz- waiting for you.

Once you see the machine, you can run it in both directions. Mal- is the workhorse of word building and it is exact: it gives the opposite, not merely the absence. So malavarulo is a generous person, malavare is generously, malavareco is generosity, and avareco is meanness. Compare malriĉa poor from riĉa rich, or malforta weak from forta, and notice that Esperanto did not have to decide which member of each pair is the "real" word. It just picked one and reversed it.

Generous with what, in practice. Malavara covers money, time, praise and portions: malavara donaco, malavara laŭdo, malavara porcio. The near neighbour is malŝparema, wasteful, and the difference matters, because a malavara person gives to somebody and a malŝparema one merely spends. Set it against ŝpari, to save or economise, and you have the whole spectrum in three roots.