As a verb, 瞎 means 'to be blind (of eyes)'. As an adverb, it means 'blindly, foolishly, to no purpose' — criticizing actions done without thought or reason. Unlike 盲目 (máng mù), which describes a lack of awareness or discernment (often in formal contexts), 瞎 is more colloquial and implies the action is pointless or foolish. 白白 (bái bái) focuses on wasted effort ('in vain'), while 一味 (yī wèi) implies stubborn persistence in a negative habit.