Should "Holler Nuff" be considered archaic?

The fact that it does not appear in a dictionary, is not enough to call a word or phrase "archaic".

I should imagine that the phrase is still used - it is very informal.

Holler nuff = Call out "Enough!" i.e. admit that you have been defeated.

OED

hollo | hollow | holla, v.

Etymology: Connected with holla int., hollo int.; also with hallo int. and hallow v.2

1.a. intransitive. To cry out loud, to shout, vociferate; to halloo.

1642 T. Fuller Holy State ii. xix. 122 'Tis madnesse to holloe in the ears of sleeping temptation.

1919 Louisiana reports, Volume 143 Mr. Sandlin was in his yard, in sight of us, and as we were going up by the side of the fence, he hollowed at us, and we stopped.

holler, v.

Etymology: variant of hollo v. (dialect and U.S.)

To cry out loud, to shout; to complain. In a fight: to give up, to cry ‘enough’

1926 J. Black You can't Win iv. 43 Holler before you're hurt; that's my motto.

1969 Times 22 July (Moon Report Suppl.) p. ii/3 When Colonel Aldrin jumped off the last step of the moon ladder..everyone in the Aldrin home was whooping and hollering.