idiosyncrasy (n.)

• aberration
• abnormality
• animus
• anomaly
• aptitude
• aroma
• attribute
• badge
• banner
• bent
• bias
• brand
• cachet
• cast
• character
• characteristic
• conceit
• configuration
• constitution
• crank
• crankiness
• crotchet
• crotchetiness
• cut
• deviation
• device
• diathesis
• differentia
• differential
• disposition
• divergence
• earmark
• eccentricity
• feature
• figure
• flavor
• freakishness
• grain
• gust
• habit
• hallmark
• image
• impress
• impression
• inclination
• index
• indicant
• indicator
• individualism
• insignia
• irregularity
• keynote
• kidney
• kink
• leaning
• maggot
• make
• makeup
• mannerism
• mark
• marking
• measure
• mettle
• mind
• mind-set
• mold
• nature
• nonconformity
• note
• oddity
• odor
• particularity
• peculiarity
• picture
• predilection
• predisposition
• preference
• proclivity
• propensity
• property
• quality
• queerness
• quip
• quirk
• quirkiness
• representation
• representative
• savor
• seal
• set
• shape
• sign
• signal
• signature
• singularity
• slant
• smack
• specialty
• stamp
• strain
• strangeness
• streak
• stripe
• symptom
• taint
• tang
• taste
• temper
• temperament
• tendency
• token
• trademark
• trait
• trick
• turn
• twist
• type
• unconventionality
• unnaturalness
• warp
• whim
• whimsicality
• whimsy