Learner's definition of OVERTURE
1 : a piece of music played at the start of an opera, a musical play, etc. 2 : something that is offered or suggested with the hope that it will start a relationship, lead to an agreement, etc.
The government has made a significant peace overture by opening the door to negotiation.
He was making (romantic/sexual) overtures to her during dinner.
The company's board rejected overtures [=offers] for a merger.
3 : the first part of an event: the beginning of something