breach

(noun) a failure to perform some promised act or obligation.

(noun) an opening (especially a gap in a dike or fortification).

(noun) a personal or social separation (as between opposing factions). Synonyms: rupture, break, severance, rift, falling out. Examples: "They hoped to avoid a break in relations."

(verb) act in disregard of laws, rules, contracts, or promises. Synonyms: transgress, offend, infract, violate, go against, break. Examples: "Offend all laws of humanity." "Violate the basic laws or human civilization." "Break a law." "Break a promise."

(verb) make an opening or gap in. Synonyms: gap.