Nouns

(n)combat, armed combatan engagement fought between two military forces
(n)fight, fighting, combat, scrapthe act of fighting; any contest or struggle“a fight broke out at the hockey game”, “there was fighting in the streets”, “the unhappy couple got into a terrible scrap”

Verbs

(v)battle, combatbattle or contend against in or as if in a battle“The Kurds are combating Iraqi troops in Northern Iraq”, “We must combat the prejudices against other races”, “they battled over the budget”