Breasts that are larger than large breasts but smaller than gigantic breasts.
Larger than the character's head, but less than twice the size of their head.
Until we have more/better examples, see huge breasts on the Danbooru wiki.
Few posts with huge_breasts, large_breasts and 2girls (but many with 1girl!)
Very few posts with gigantic_breasts, huge_breasts and 2girls (but many with 1girl!)
The following tags are aliased to this tag: huge_boobs and huge_tits (learn more).
This tag implicates breasts (learn more).