A slang term that is given to Fifth Graders at a Junior High School. It is usually derogatorily used by older students to make fun of the younger, less knowledgeable Fifth Graders. It is similar to the way in which people in High School like to make fun of the Freshman.
Fifth Grader: "What are you guys doing?"

Seventh & Eighth Graders: "Nothing.Go away, you stupid fifthy!"
by ThatOneDefinitionsGuy June 6, 2014
Get the fifthy mug.
Yooo whats up smithy fifthy
I love you smithy fifthy
Smithy you are short as fuck
by Beefers queefers July 7, 2022
Get the Smithy fifthy mug.