You Do Need power plug adapter while traveling from Belize to Lebanon.

Here is Why You Need An Adapter

The outlet and plug type used in Lebanon are C, D and G and in Belize are A, B and G. This is how they look like.

Belize

In Belize, outlets of type A, B and G are in use.

Type A

Type B

Type G

Lebanon

In Lebanon, outlets of type C, D and G are in use.

Type C

Type D

Type G