VERGUÍSIMA VERGA means penis, specially in Spain; Ísimo, ísima are spanish augmentatives. So its hard to define because the augmentative applies to adjetives not to nouns but it is urban slang meaning a huge penis. The correct augmentative is VERGOTA
Synonyms of verguisima are vergota
Used in Spain as well
"She took the huge penis in her mouth. Se metió la verguísima en su boca"