utmost
utmost adjective [ always before noun ]formal uk/ˈʌtməʊst/ us
used to emphasize how important or serious something is
крайний, предельный
a matter of the utmost importance The situation needs to be handled with the utmost care.
UTMOST noun
uk/ˈʌtməʊst/ us do your utmostto try as hard as you can to do something
делать все возможное
[ + to do sth ] We did our utmost to finish the project on time.