Webster's 1913 Dictionary
IDIOSYNCRATIC; IDIOSYNCRATICAL
IDIOSYNCRATIC; IDIOSYNCRATICAL Id `i *o *syn *crat "ic, Id `i *o *syn *crat "ic *al, a.
Defn: Of peculiar temper or disposition; belonging to one's peculiar and individual character.
New American Oxford Dictionary
idiosyncratic
id i o syn crat ic |ˌidēəsiNGˈkratik, ˌidē -ō- ˈˌɪdiəsɪŋˈˌkrædɪk | ▶adjective of or relating to idiosyncrasy; peculiar or individual: she emerged as one of the great idiosyncratic talents of the Nineties. DERIVATIVES id i o syn crat i cal ly |-ik (ə )lē |adverb ORIGIN late 18th cent.: from idiosyncrasy, on the pattern of Greek sunkratikos ‘mixed together. ’
Oxford Dictionary
idiosyncratic
idiosyncratic |ˌɪdɪə (ʊ )sɪŋˈkratɪk | ▶adjective relating to idiosyncrasy; peculiar or individual: she emerged as one of the great, idiosyncratic talents of the nineties. DERIVATIVES idiosyncratically adverb ORIGIN late 18th cent.: from idiosyncrasy, on the pattern of Greek sunkratikos ‘mixed together ’.
American Oxford Thesaurus
idiosyncratic
idiosyncratic adjective of the great idiosyncratic detectives of fiction, Nero Wolfe is my favorite: distinctive, individual, individualistic, characteristic, peculiar, typical, special, specific, unique, one-of-a-kind, personal; eccentric, unconventional, irregular, anomalous, odd, quirky, offbeat, queer, strange, weird, wacky, wingy, bizarre, freakish, abnormal; informal freaky, far out, off the wall.
Oxford Thesaurus
idiosyncratic
idiosyncratic adjective each researcher had his or her own idiosyncratic interest | some might think this a rather idiosyncratic approach: distinctive, individual, characteristic, distinct, distinguishing, peculiar, individualistic, different, typical, special, specific, representative, unique, personal, private, essential; eccentric, unconventional, uncommon, abnormal, irregular, aberrant, anomalous, odd, quirky, queer, strange, weird, bizarre, outlandish, freakish, extraordinary; rare singular.
Sanseido Wisdom Dictionary
idiosyncratic
id i o syn crat ic /ɪ̀diəsɪŋkrǽtɪk /形容詞 特異な, 特質的な .ì d i o syn cr á t i cal ly 副詞