See also
eccentric. The
English frequently use the word to describe one who is slightly odd, displaying somewhat bizarre behaviour.
Classic examples include Screaming Lord Sutch (a "real-life Austin Powers"), who was once described by a BBC radio announcer as "leader of the pottiest political party" and Patrick Moore, that well-known and much-loved astronomer with a penchant for the glockenspiel and fast-talking enthusiasm.
The classic maiden aunt (every family seems to have one), who wears a tea cosy for a hat, and brightly-coloured (frequently unmatched) socks also falls under the purview of this excellent word.
One who is potty falls between being a raving nutter and barmy.
In keeping with the occasionally economical nature of the English language, "potty" has other uses too, notably connected with *ahem* toilets. The word also refers to the infamous chamber pot (kept out of the way, most frequently under the bed), although nowadays it most often refers to a plastic vessel used for training children to "go". On that note, I have to say that I find it quite cute when people speak of "going to the potty".