"Imatation" spelled backwards. Used as a seemingly harmless word to describe someone of either gender who is: an annoying braggart, a B.S. artist, an egotist, is shallow, fake, two faced, and/or self-centered, and/or all of the above. Usually said "person" is so-full-of-themselves that they never figure out what the word is or means!
"Ha! Listen to that Mikey talken' about single-handedly winning the football game! Like we didn't help. What a noitatami!!"