If both carbon atoms connected by a double bond are members of a ring, the double bond is said to be endocyclic; if only one of them is a member of a ring, the double bond is said to be exocyclic.
eg:
Endocyclic
OChemPal
If both carbon atoms connected by a double bond are members of a ring, the double bond is said to be endocyclic; if only one of them is a member of a ring, the double bond is said to be exocyclic.
eg: