The etymology is interesting: From AHD:
champerty

SYLLABICATION: cham·per·ty
PRONUNCIATION: chmpr-t
NOUN: Inflected forms: pl. cham·per·ties
A sharing in the proceeds of a lawsuit by an outside party who has promoted the litigation.
ETYMOLOGY: Middle English champartie, from Old French champart, the lord's share of the tenant's crop, from Medieval Latin campars, camppars : Latin camp, genitive of campus, field + Latin pars, part; see part.
OTHER FORMS: champer·tous (-ts) —ADJECTIVE