to advance beyond proper, established, or usual limits; make gradual inroads: A dictatorship of the majority is encroaching on the rights of the individual.
2.
to trespass upon the property, domain, or rights of another, especially stealthily or by gradual advances.
Origin: 1275–1325; Middle English encrochen < Anglo-French encrocher,Old French encrochier to catch hold of, seize, equivalent to en-en-1 + -crochier, verbal derivative of croc hook < Germanic; see crooked, crook
early 14c., from O.Fr. encrochier "seize, fasten on, perch," lit. "to catch with a hook," from en- "in" + croc "hook," from O.N. krokr "hook." Sense of "trespass" is first recorded 1530s. Related: Encroached; encroaches; encroaching.