inside joke

:  an interior or internal part or place :  the part within

:  inward nature, thoughts, or feeling

:  viscera, entrails

:  on the inner side

:  in or into the interior

:  to or on the inside

:  of, relating to, or being on or near the inside

:  relating or known to a select group

:  behind-the-scenes

:  in or into or as if in or into the interior of

:  on the inner side of

:  within

:  something said or done to provoke laughter

:  a brief oral narrative with a climactic humorous twist

:  the humorous or ridiculous element in something

:  to make jokes :  jest

:  to make the object of a joke :  kid