tact

Tact originally denoted the ‘sense of touch’ (that is what Alexander Ross was referring to when he wrote ‘Of all the creatures, the sense of tact is most exquisite in man’, Arcana microcosmi 1651). But by the end of the 18th century it had evolved semantically via ‘refined faculty of perception’ to ‘skill in behaving or speaking with propriety or sensitivity’. It was acquired via French tact from Latin tactus ‘sense of touch’, a noun use of the past participle of tangere ‘touch’ (source of English contact, tangent, tangible, etc). Tactile (17^th c.), from the Latin derivative tactilis, preserves the original notion of ‘touching’.