expression, godan verb (-su)
Used when someone feels safe enough to be open and unguarded with another person. Often appears in negative forms like 心を許せない or 心を許していない.
彼にはまだ心を許せない。
I still can't let my guard down with him.
長い付き合いで、ようやく心
After a long relationship, I've finally come to be able to trust him.