barmy
1. adjective
mad; eccentric UK, 1851
2. noun
a mad or eccentric person. Derives from barm, a dialect term for 'yeast'. An early source remarks 'frothing like barm hence, full of ferment, flighty, empty-headed'. It is probably relevant to note also the lunatic asylum built in 1828 at Barming Heath, Kent (now the site of Maidstone Hospital) UK, 2001