An emphasis of the word "Shit" commonly used in
reverence or awe. "she-aht" is the
phonetic pronunciation, drawn out, once again, to emphasize the word and make a phrase similar to "holy shit"
and the like while sounding more badass.
"Is that you, Rick? Under all that
man bush? Shiat.... I would NOT have messed with that guy."
~
Negan, The Walking Dead; Season 7,
episode 4