IHS is 'The Indian High School' the shittiest school in all of existence. IHS can also be told as "I HATE SCHOOL". Another thing is reversing 'THIS' which makes it look like 'SHIT' because the school is shit.
Example: "So, ih the girls at the party weren't as hot as I thought."
"IH, I really don't know if going to three pre-games was a good idea."
"ih, I really should have studied for that test."
common street version of the verb 'is.' that's third person singular, present tense, for all you grammarians out there.
Past tense would accordingly be, 'wuh.'
Example: "Mane, temps around here ih cold, yo. Ten degree out, and I'm thinkin' we in 313. Lions still weak."