Synonyms and related words :
encroachment, entrance, entrenchment, impingement, imposition, incursion, infiltration, influx, infringement, injection, inroad, insinuation, interagency, intercession, interference, interjection, interloping, intermediation, interposure, interruption, intervention, intrusion, invasion, involvement, irruption, mediation, obtrusion, stepping in, trespass, trespassing, unlawful entry