Billy club and Slingshot

Billy club noun - A heavy rigid stick used as a weapon or for punishment.

Slingshot and billy club are semantically related In some cases you can use "Slingshot" instead a noun phrase "Billy club".

Slingshot noun - A plaything consisting of a Y-shaped stick with elastic between the arms; used to propel small stones.

Billy club and slingshot are semantically related in arm topic. Sometimes you can use "Billy club" instead a noun "Slingshot".