Verb

(head)

(infringe)

Verb

(en-verb)

Break or violate a treaty, a law, a right etc.

*{{quote-magazine, date=2013-06-08, volume=407, issue=8839, page=55, magazine=(The Economist)

, title= Obama goes troll-hunting , passage=According to this saga of intellectual-property misanthropy, these creatures [patent trolls] roam the business world, buying up patents and then using them to demand extravagant payouts from companies they accuse of infringing them. Often, their victims pay up rather than face the costs of a legal battle.}}

Break in or encroach on something.