- the temperament or mental constitution peculiar to a person or group
- any personal peculiarity, mannerism, etc.
- an individual reaction to a drug, food, etc. that is different from the reaction of most people
Origin of idiosyncrasyClassical Greek idiosynkrasia from idio-, one's own, peculiar (see idio-) + synkrasis, a mixing together, tempering from synkerannynai, to mix together from syn-, together + kerannynai, to mix from Indo-European an unverified form ?ere-, to mix from source rare, German rühren, to stir