tact [M17th] Tact in early examples referred to the sense of touch. It comes from Latin tactus ‘touch, sense of touch’, from tangere ‘to touch’. The word developed a notion of ‘sensitivity’ and in the late 18th century gained its modern sense ‘delicacy in dealing with others’. The Latin source also gave the English word tactile, which in the early 17th century meant ‘perceptible by touch’, and tangible [L16th]. Tangent [L16th], first used in geometry to mean ‘touching’, is also from tangere.