Used metaphorically for non-physical fights, like legal or political confrontations. The opposing political candidates will slug it out during the debates.
Pro Tip 2/3
Extended Resolution
Implies a conflict or competition that isn't resolved quickly and requires endurance. The divorce was bitter and they slugged it out for years over the assets.
Pro Tip 3/3
Not Literally Violent
Doesn't necessarily mean physical violence; often used for intense arguments or competitions. The board members slugged it out until they agreed on a new policy.