Frequency: The word is one of the 3000 most common words in English.
1.
You use ~ to describe the final result or aim of a long series of events.
He said it is still not possible to predict the ~ outcome...
The ~ aim is to expand the network further.
= eventual
ADJ: ADJ n
2.
You use ~ to describe the original source or cause of something.
Plants are the ~ source of all foodstuffs...
The ~ cause of what’s happened seems to have been the advertising campaign.
= fundamental
ADJ: ADJ n
3.
You use ~ to describe the most important or powerful thing of a particular kind.
...the ~ power of the central government...
Of course, the ~ authority remained the presidency...
ADJ: ADJ n
4.
You use ~ to describe the most extreme and unpleasant example of a particular thing.
Bringing back the death penalty would be the ~ abuse of human rights...
ADJ: ADJ n
5.
You use ~ to describe the best possible example of a particular thing.
Caviar and oysters on ice are generally considered the ~ luxury foods.
= definitive
ADJ: ADJ n
6.
The ~ in something is the best or most advanced example of it.
This hotel is the ~ in luxury...
PHRASE: PHR n/-ing, usu v-link PHR, PHR after v