大だい

prefix, na-adjective, noun

large; big; great; major; serious

Prefix or adjectival noun expressing large size, scale, importance, or severity. Common in compounds like 大問題 (major problem), 大成功 (great success), 大規模 (large-scale). As a standalone noun, it can mean 'large' in contexts like serving sizes.

• これは大だい問もん題だいだ。

  This is a major problem.

• 大だい規き模ぼな工こう事じが始はじまった。

  Large-scale construction has begun.

prefix

great; prominent; eminent; distinguished

Prefix used for people of high status or achievement, e.g., 大作家 (great writer), 大政治家 (eminent politician).

• 彼かれは大だい作さっ家かとして知しられている。

  He is known as a great writer.

suffix

-sized; as big as; the size of

Suffix attached to nouns indicating size, e.g., 手のひら大 (palm-sized), 等身大 (life-size).

• 手てのひら大だいの石いしを見みつけた。

  I found a palm-sized stone.

noun, used as a suffix

university (abbreviation)

Abbreviation of 大学, used in compound university names like 東大 (Tokyo University), 京大 (Kyoto University). Not used as a standalone word for 'university'.

See also: 大学

• 彼かれは東とう大だいの学がく生せいだ。

  He is a student at the University of Tokyo.

noun

large (serving size); large option

Used in restaurants or shops to indicate a large size, e.g., 大盛り (large portion), 大サイズ (large size).

• ラーメンは大だいでお願ねがいします。

  I'll have the large ramen, please.

noun

long month (31 days)

Abbreviation of 大の月, referring to a month with 31 days. Rare standalone use; mostly seen in calendar contexts.

See also: 大の月

• 今こん月げつは大だいだから、31日にちまである。

  This month is a long month, so it has 31 days.