relief; mitigation; alleviation; relaxation (of restrictions, tensions, etc.); easing; softening

gentle (slope, curve); slow (speed)

lenience and severity

lax; sloppy; lenient

buffer zone

buffered

gentle (curve, slope, etc.)

relaxation (e.g. of muscles); becoming flaccid

lenient

to slack off (e.g. one's work, attention); to not put one's heart in