informal Behave or talk in a very loving or sentimental way.
More example sentences
- Humans - girl and boy - can learn from the strategies of the male bird when looking for a mate with whom to bill and coo.
- My own personal wife and I hardly ever bill and coo early in the morning any more.
- In The Abdication, they bill and coo once again-this time with spiritual fervor.
Definition of bill and coo in:
- The US English dictionary