lock horns
• engage in conflict.
• "drug companies are locking horns in a legal battle over patents"
Similar:
quarrel,
disagree,
have a dispute,
wrangle,
bicker,
be at odds,
be at loggerheads,
lock antlers,
cross swords,
fight,
do battle,
engage in conflict,
contend,
challenge,
have a dust-up,
have a scrap,
have a barney,
