co ‧ hort /ˈkəʊhɔːt $ ˈkoʊhɔːrt/ BrE AmE noun [countable]
[ Date: 1400-1500 ; Language: Latin ; Origin: cohors 'enclosed place, people in an enclosure, unit of soldiers in the ancient Roman army' ]
1 . someone’s cohorts are their friends who support them and stay loyal to them – used in order to show disapproval:
Mark and his cohorts eventually emerged from the studio.
2 . technical a group of people of the same age, social class etc, especially when they are being studied:
a cohort of 386 patients aged 65 plus