Definition

A witty insult implying someone is the son of a tool (i.e., a fool or idiot), with the ironic twist that it also makes the accuser a tool for parenting one. It's self-defeating mockery at its finest.

Example Usage

Dad called me a toolson, but I pointed out that made him the original tool.

Source: Urban Dictionary (https://www.urbandictionary.com/define.php?term=toolson&defid=6823088)