deep ‧ en /ˈdiːpən/ BrE AmE verb
[ Word Family: noun : ↑ deep , ↑ depth ; adjective : ↑ deep , deepening; verb : ↑ deepen ; adverb : ↑ deeply ]
1 . GET WORSE [intransitive] if a serious situation deepens, it gets worse – used especially in news reports:
The recession continues to deepen.
a deepening international crisis
2 . BECOME STRONGER [intransitive and transitive] to become stronger or greater, or to make something stronger or greater:
Jeanne liked Simon as a friend but she did not want the relationship to deepen.
The idea only deepened his gloom.
The mystery deepened (=became even more mysterious) .
Students explore new ideas as they deepen their understanding (=understand more) of the subject.
3 . EXPRESSION ON SB’S FACE [intransitive] literary if someone’s smile or ↑ frown deepens, they smile even more or frown even more:
Her worried frown deepened.
4 . WATER [intransitive and transitive] if water deepens, or if someone deepens it, it becomes deeper:
The river deepens beyond the town.
The harbour was deepened to take bigger boats.
5 . COLOUR [intransitive] literary if light or a colour deepens, it becomes darker:
The twilight deepened.
6 . SOUND [intransitive] if a sound deepens, it becomes lower:
His voice deepened as he relaxed.
7 . BREATH [intransitive] if your breathing deepens, you take more air into your lungs