Frequency: The word is one of the 3000 most common words in English.
1.
An ~ person or animal has a quality of anger and determination that makes them ready to attack other people.
Some children are much more ~ than others...
Aggressive behaviour is a sign of emotional distress.
= belligerent
ADJ
~ly
They’ll react ~ly.
ADV
~ness
Her ~ness made it difficult for him to explain his own feelings.
= aggression
N-UNCOUNT
2.
People who are ~ in their work or other activities behave in a forceful way because they are very eager to succeed.
He is respected as a very ~ and competitive executive...
ADJ
~ly
...countries noted for ~ly pursuing energy efficiency.
ADV: usu ADV with v