Hint #1: From 20A, 28A, 45A, 54A - the meta answer is a 13-letter word, has 3 syllables, 4 unique letters, and the only vowel is E... from 70A, the four letters in the word are L, E, N, and S
Hint #2: the answer relates to the title... the meta answer means "the state of being preposterous"
Hint #3: [smell or taste, for example] + [opposite of more] + [Loch ___ monster]