dead tired 

extremely tired; energy was drained because of too much exhaustion

I was dead tired after 12 straight hours of work.

dead tired by Joorassic November 19, 2013

Dead man tired 

So tired you are unable to move and appear to be deceased to the naked eye.

I pulled an all nighter last night and now I am dead man tired.

Dead man tired by Humanbean201513 November 18, 2018

Dead Dick Tired 

<<Adj>> 1) So tired your dick disappears. 2) Abbreviated DDT: Broken bicycle axle.

I must have been dead dick tired when I accidentally pissed in my laundry hamper this morning. I DDT'ed on some bots dots last night on my way home from work.

Dead Dick Tired by JPickwick March 22, 2011