I. ut ‧ most 1 /ˈʌtməʊst $ -moʊst/ BrE AmE ( also uttermost ) adjective
[ Language: Old English ; Origin: utmæst 'farthest out' , from ut 'out' ]
the utmost importance/respect/care etc the greatest possible importance etc:
a matter of the utmost importance
I have the utmost respect for her accomplishments.
Baldwin treated the matter with the utmost seriousness.
II. utmost 2 BrE AmE noun [singular]
the most that can be done
to the utmost
Both runners had pushed themselves to the utmost.
The medical staff did their utmost (=tried as hard as they could) to save the patient’s life.