The phrase "had flash" typically refers to a sudden moment of realization or insight. Antonyms for this phrase would therefore include terms that describe confusion, misunderstanding, or lack of comprehension. Words such as cloudy, dim, unclear, murky, or hazy can be used to convey the opposite of "had flash." Additionally, words like oblivious, unaware, or ignorant can be used to describe a lack of awareness or understanding, which is antithetical to the sudden enlightenment that "had flash" suggests. Furthermore, terms like perplexed, mystified, or befuddled convey a state of confusion or puzzlement, which is the opposite of the clarity and understanding associated with "had flash.