(informal)commit oneself to a course of action about which one is nervous
(非正式)冒险尝试
To begin an unfamiliar venture, especially after hesitating
冒险，采取断然行动，结婚：开始进行一次不熟悉的冒险，尤其是在踌躇一阵之后
After a three-year engagement, they're finally taking the plunge.
订婚三年后，最终他们结婚了