He 'kept/maintained his cool' [=he didn't get angry or upset] even though it was clear that he was being unfairly treated.
He was struggling to 'maintain his cool/composure'. [=he was struggling not to become angry or upset]
They barely had enough food to 'maintain life'. [=to make it possible for life to exist or continue]
(..) She just talked me into something called the Orbital Paste Wax Buff. Oh, yeah. No, it's very important to maintain your clear coat. Boy, once that goes-- Oh, yeah. Um, hi. Hi. Bogdan was averaging (..)2011 TvShow: Breaking Bad Title: Problem Dog Season: 4 Episode 7