What is a "tool"?

One usage of the word originates from the UK where it means ‘idiot’. It’s a fairly light-hearted insult and actually a bit softer than idiot and would be used to poke fun at someone. You wouldn’t, for instance, say “he was a f***ing tool”. I’d say it’s not used as much now and has been overtaken by ‘nob’ in recent years.

A person who is “used”.
Example: a person unaware of having fake friends.

I’ve always used “tool” to mean a person (usually a man) who is arrogant as well as cluelessly and undeservedly stuck on himself, e.g. Kevin Federline.

I’ve heard of people using it as in Triozoo’s example also.

Recently it’s come to be synonymous with “dick.”

I agree with Triozoo it’s a person who is used, who follows what others tell him/her to do, i.e. a frat guy…

The way I use it is like, if someone seems like they are easily influenced by others hence they are someones “tool” or just a tool to be used by someone. Like, did you see that guy, yeah he had some ridiculous tattoos and was all saggin his pants, yeah i know, what a tool. It seems similiar to calling someone a loser, but defining why they are a loser.

here, check out tool

Bush.

Generally something like this

@uberbatman lol spot on, guidos came to mind too when I thought of tool