The phrase "in a happy-go-lucky fashion" can be replaced with various synonyms, including carefree, lighthearted, breezy, nonchalant, amiable, jovial, mirthful, and cheerful. All these words indicate an attitude of joy and merriment, showing that a person is living a life free of worries and stress. They describe someone who is taking life in stride, enjoying each moment and spreading positivity wherever they go. People who exude this carefree energy are often viewed as likable and approachable, with a demeanor that puts others at ease. Overall, using any of these synonyms helps to convey the same meaning of living life to the fullest in a carefree and joyful manner.