Green’s Dictionary of Slang

shitless adv.

to an extreme extent.

[US]E. Hemingway letter 11 June in Baker Sel. Letters (1981) n.d. 696: I’d done 42 galleys from 0600 to 1300 and was bored shitless. [Ibid.] 852: 5 Dec.: You are probably bored shitless by now.
[US]W. Eastlake Castle Keep (1966) 145: I’ll bore them shitless with military tactics.
[US]B. Malamud Tenants (1972) 56: On my first solo gig I was bagged out of my own stupidity, beaten shitless, and dumped in jail.
[Aus]Tracks (Aus.) Dec. 3: Don’t listen to all the shit that gets put on Victoria. Victorians know they have the best state, they don’t have to rave shitless [Moore 1993].
[Aus]D. Maitland Breaking Out 263: Sweating in the fierce heat of the quadrangle and already bored shitless by the whole affair.
[Aus]R. Fitzgerald Pushed from the Wings (1989) 68: Merv’s worried shitless.
[US]P. Munro Sl. U. 208: worried shitless very worried.
[Scot]I. Welsh Filth 71: Bored shitless here.
[US]N. Green Angel of Montague Street (2004) 215: I was bored shitless most of the time.
[UK]G. Malkani Londonstani (2007) 277: Guys [...] that he’d beaten shitless over the years.
[Aus]L. Redhead Cherry Pie [ebook] Bored shitless by all those old farts talking politics.
[Aus]G. Disher Heat [ebook] Saturday afternoon, bored shitless and counting the minutes until she knocked off.

In phrases