1.
You can use ~ to emphasize the importance or seriousness of something or to emphasize the way that it is done.
It is a matter of the ~ urgency to find out what has happened to these people...
Security matters are treated with the ~ seriousness...
You should proceed with the ~ caution...
ADJ: ADJ n emphasis
2.
If you say that you are doing your ~ to do something, you are emphasizing that you are trying as hard as you can to do it. (FORMAL)
He would have done his ~ to help her, of that she was certain...
N-SING: poss N emphasis
3.
If you say that something is done to the ~, you are emphasizing that it is done to the greatest extent, amount, or degree possible.
My limited diplomatic skills were tested to the ~...
The best plan is to continue to attack him to the ~ of our power.
PHRASE: usu PHR after v emphasis