lenient

Lenient comes from Middle French lénient, from Latin lēniēns, the present participle of lēnīre, meaning 'to soften or soothe.' That verb in turn traces back to lēnis, meaning 'soft.'

The word's roots stay close to its meaning throughout — from 'soft' to 'soothing' to a present participle describing something in the act of softening, arriving in English still carrying that sense of easing rather than hardening.

It shares its root lēnis ('soft') with lēnīre ('to soften, soothe'), the Latin verb that gave lenient its shape.