Peanut and Small fry

Peanut noun - A young child who is small for his age.

Small fry and peanut are semantically related In some cases you can use "Small fry" instead the word "Peanut" as an adjective or a noun.

Small fry noun - A young person of either sex.

Peanut and small fry are semantically related in small topic. Sometimes you can use "Peanut" instead an adjective phrase "Small fry", if it concerns topics such as kept from growing.