The precise meaning "худой" in маленькая война, окончившаяся худым миром
must be found in the adverb (or predicative) худо
, not in the adjective худой
.
Compare the scattered meanings of худой
, and the word худо
, that has precise, exactly one meaning -- ill, badly
.
The same scattered meanings will be exists for other words (not for all, of course), which can be narrowed down to its underlying definition by look up its adverb or predicative with the same root in a dictionary:
крепкий -> крепко
вольный -> вольно
любимый -> любо
сухой -> сухо
Rule of thumb: try to find a word as close (short) to the stem (root) as possible.