Ichidan/ru-verb

1. to loosen; to slacken
2. to relax (attention, efforts, etc.); to let down (one's guard); to relieve (tension)
3. to relax (a rule); to ease (e.g. restrictions); to loosen (control)
4. to reduce (speed); to slow down; to ease up
5. to make more gradual (of a slope)