Dope

n.

Heard in Dublin, Offaly and Wexford

A foolish, simple-minded, or gullible person who frequently makes a show of themselves.

In use

Will you look at yer man droppin' his keys down the drain, what an absolute dope!

Posh English

Observe that gentleman dropping his keys into the drainage grate, what a complete and utter fool.

Same phrase, other counties