noun which may take the genitive case particle 'no', na-adjective, noun
double extra-large; XXL; 2XL
Used for sizes larger than 特大 (extra-large), often in clothing, food portions, or product sizes. The prefix 超 emphasizes exceeding the already large standard.
このTシャツは超特大サイズです。
This T-shirt is a double extra-large size.
超特大のポテトを注文した。
I ordered a double extra-large fries.
大 is the basic 'large' size; 超特大 is several steps above.
Compound of 超 (chō, 'super' or 'ultra') + 特大 (tokudai, 'extra-large'). The prefix 超 intensifies the size beyond the already large 特大.