Filly and Gee-gee

Filly noun - A female person who has not yet reached adulthood.

Gee-gee and filly are semantically related. In some cases you can use "Gee-gee" instead a noun "Filly".

Gee-gee noun - A word for horse used by children or in adult slang.

Filly and gee-gee are semantically related. You can use "Filly" instead a noun phrase "Gee-gee".