ENCROACHMENT, n. The entering gradually on the rights or possessions of another, and taking possession; unlawful intrusion; advance into the territories or jurisdiction of another,by silent means, or without right. 1. That which is taken by encroaching on another. 2. In law, if a tenant owes two shillings rent service to the lord, and the lord takes three, it is an encroachment.
Encroachment En*croach"ment, n. 1. The act of entering gradually or silently upon the rights or possessions of another; unlawful intrusion. An unconstitutional encroachment of military power on the civil establishment. --Bancroft. 2. That which is taken by encroaching on another. 3. (Law) An unlawful diminution of the possessions of another.
(encroachments) You can describe the action or process of encroaching on something as encroachment. (FORMAL) It's a sign of the encroachment of commercialism in medicine...N-VAR: usu with supp [disapproval]