The thing is, while an American dilly is someone remarkable (like you) an Australian dilly is, well, someone idiotic (unless dilly is short for dilly bag, which is a bag made of plaited grass that's generally used for carrying food).
In Britain, however, no one will understand either meaning of the word dilly, though dilly-dally, meaning to faff about with unimportant things instead of getting on with an important one, is well-known. Sometimes dilly-dally is split up into dilly and dally, both meaning dilly-dally, as in the famous song:
My Old Man said: 'Foller the van
And don't dilly-dally on the way.'
Off went the van wiv me 'ome packed in it
I walked be'ind wiv me old cock linnet
But I dillied and dallied,
Dallied and dillied
Lost me way and don't know where to roam.
And you can't trust a 'Special'
Like an old-time copper
When you can't find your way home.
(Explanation: the singer and her husband are moving home. There isn't room for the lady on the removal van, so she has to walk behind carrying her pet bird. A 'Special' is a volunteer policeman; a copper is a paid policeman.)
It's a song I've always particularly disliked, but here's a version if it will give you pleasure:
I suppose it's cheerful, anyway.
Word To Use Today: dilly. The American version of this word might come from the girl's name, or perhaps as a shortening of delightful; the Australian one might be an echo of silly. The bag comes from the Native Australian Jagera language, and dilly-dally is the same word as dally, with the dilly added for fun. This word dates back to the 1600s.