ガイgai

1. nounguy

• Synonym男おとこNeutralThe most general word for a man; also covers manliness, as in 「男を上げる」. 「ガイ」 is a loanword with a playful, casual feel.
• Synonym男性だんせいNeutralFormal, objective word for the male sex, as in 「男性用」; lacks the affectionate, teasing tone of 「ガイ」.
• Synonym男の人おとこのひとNeutralA polite, neutral way to say an adult man; softer than 「男」.
• RelatedやつCasualColloquial 'that guy' with a casual or contemptuous nuance; can refer to things as well as people.
• Related野郎やろうCasualColloquial and rough for 'that guy'; also used as an insult, as in 「この野郎」.
• Related男子だんしNeutralBoys or males, as in 「男子校」 and 「男子トイレ」; leans toward objective classification by sex.
• Related若者わかものNeutralYoung people, regardless of sex; 「ガイ」 refers only to men.
• Related少年しょうねんNeutralBoys or juveniles, typically minors; not used for grown men.
• Related兄ちゃんにいちゃんCasualColloquial address for a young man, warm and casual; also an affectionate term for one's own older brother.
• Related兄さんにいさんNeutralAn older brother, or a friendly way to address a young man; slightly more polite than 「兄ちゃん」.
• Related奴さんやっこさんCasualColloquial pronoun for 'that person', with affection or exasperation; rare and not limited to men.
• Related雄ゆうWrittenWritten style for an outstanding figure or leader, as in 「一方の雄」; heroic, not everyday 'guy'.
• Related成人男性せいじんだんせいFormalFormal term for adult males, common in statistics, medical writing and other objective contexts.

For a man in general, use 「男」 or 「男性」; politely, 「男の人」. 「ガイ」 is a playful loanword, as in 「ナイスガイ」 and 「タフガイ」. For 'that guy' said offhand, use 「奴」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 男性だんせいから見みて尊敬そんけいできる男おとこ。