idiosyncrasy
[noun]
Synonyms: peculiarity, characteristic, eccentricity, mannerism, oddity, quirk, trick

[TahlilGaran] English Synonym Dictionary ▲

id‧i‧o‧syn‧cra‧sy /ˌɪdiəˈsɪŋkrəsi/ noun (plural idiosyncrasies) [countable]
[Date: 1600-1700; Language: Greek; Origin: idiosynkrasia, from idio- ( ⇒ idiolect) + synkerannynai 'to mix together']

1. an unusual habit or way of behaving that someone has:
my uncle’s idiosyncrasies

2. an unusual or unexpected feature that something has:
one of the many idiosyncrasies of English spelling
—idiosyncratic /ˌɪdiəsɪnˈkrætɪk◂/ adjective

[TahlilGaran] Dictionary of Contemporary English ▲