What does 大文字 mean?
大文字 is a Japanese noun meaning “uppercase letters” in English. It can also be translated as “large character, the (kanji) character "dai" meaning "big", huge character "dai" formed by fires lit on the side of a mountain in Kyoto on August 16 each year” depending on context. It is written as 大文字 in kanji, おおもじ in hiragana, and oomoji in romaji. This word is part of JLPT N4 vocabulary.
Example sentence
アルファベットを大文字で書きなさい。
Write the alphabet in capitals.