The word "flippest" is spelled as /ˈflɪpəst/. It is the superlative form of the verb "flip," meaning to turn over or to toss in a quick, sharp motion. The -est suffix added to the end of the word denotes the highest degree of flipping, making it the most intense form of the action. This spelling follows the typical rule in English for adding -est to form superlatives from adjectives and adverbs.