When someone "jumps in with both feet," they are committing to a task or situation fully and without hesitation. There are many synonyms that can be used to convey a similar meaning, such as "dives in headfirst," "throws oneself into the deep end," "takes a leap of faith," and "embraces with gusto." These phrases all emphasize the idea of wholeheartedly taking on a challenge, often with enthusiasm or bravery. Other similar expressions include "goes all out," "takes the plunge," "throws caution to the wind," and "dives in feet first." Whatever the phrase, the sentiment remains the same: taking risks and embracing challenges can lead to great rewards.