(n.) A natural inclination; disposition to do good or evil; bias; bent; tendency; as a propensity to err\.

a thing for affinity an ear for an eye for animus aptitude aptness bent bias capacity for cast character conatus conduciveness constitution delight diathesis disposition eagerness eccentricity fancy fascination favor feeling for felicity flair genius for gift for grain idiosyncrasy inclination inclining individualism innate aptitude kidney leaning liability liking make makeup mental set mettle mind mind-set mold mutual affinity mutual attraction nature partiality penchant predilection predisposition preference prejudice probability proclivity proneness readiness sensitivity to set slant soft spot stamp strain streak stripe susceptibility sympathy temper temperament tendency tropism turn turn for turn of mind twist type warp weakness willingness