I think it's just an abbreviation of ノーカウント.

@@ -9,0 +10 @@
+<field>&sports;</field>
@@ -11,7 +12,2 @@
-<misc>&col;</misc>
-<gloss>not counting (as anything significant)</gloss>
-</sense>
-<sense>
-<pos>&int;</pos>
-<misc>&col;</misc>
-<gloss>that didn't count!</gloss>
+<gloss>not counted (in the score)</gloss>
+<gloss>not tallied</gloss>

https://dictionary.goo.ne.jp/word/ノーカン/
「ノーカウント」の俗な言い方。

https://ja.hinative.com/questions/19446750
As in: "That goal does not count!"
or: "You cheated, it doesn't count!"
--
So it literally means "no count."
But in English this should be "Doesn't count."

Daijs marks 俗.  sankoku just lists it without comment at the end of ノーカウント. 

Let's call [2] wishful thinking on my part. I know why we don't have a natural gloss, but it would be nice if we could cajole one in here somehow. Maybe just replace [1] with:
   not counting (as in "that didn't count")

Just saw this in an anime a couple times. Protagonist said/did something seemingly hypocritical, got called on it, reacted frantically with  "ノーカン.ノーカンでお願いします".　The first of those feels like an interjection. Here's the official translation:
"That didn't count! Please don't count that!"

Same character, next episode, falls into a bush that's covered in fertilizer(manure).  When his love interest explains to him that the bush has just been fertilized, he starts frantically trying to wipe himself off, while yelling:
３秒ルール！ ノーカン！　ノーカンだよね！

The first, again, felt like an interjection to me. Official translation:
Three-second rule! That didn't count... \NThat didn't count, right?

@@ -10,0 +11 @@
+<misc>&col;</misc>
@@ -11,0 +13,5 @@
+</sense>
+<sense>
+<pos>&int;</pos>
+<misc>&col;</misc>
+<gloss>that didn't count!</gloss>

Entry created