Definition of fish in the sea —used to say that there are many more people available for a romantic relationship I know youre sad because you and your boyfriend broke up, but hes not the only fish in the sea. Youre right. There are many/plenty more fish in the sea.

What does the biggest fish in the sea mean?

informal. —used to say that there are many more people available for a romantic relationship I know youre sad because you and your boyfriend broke up, but hes not the only fish in the sea. Youre right.