1. extra extra extra large - Noun
2. extra extra extra large - Adjective
(uncountable) One of several sizes to which an item may be manufactured.
Synonyms: XXXL, 3XL
(countable) An item labelled or denoted as being that size.
(countable) One who fits an item of that size.
(especially clothing) That is extra extra extra large (the manufactured size).
Used other than figuratively or idiomatically: see extra, large.
Source: en.wiktionary.org