Colloquial, often affectionate term for someone who drinks a lot of alcohol. Not strongly derogatory; can be used self-deprecatingly or jokingly.
My dad is a big drinker and never misses his evening drink.
He's a heavy drinker, so he always stays until the very end at drinking parties.
More neutral term for a drinker; 飲ん兵衛 is more colloquial and carries a slightly humorous or affectionate tone.
Abbreviation of アルコール中毒 (alcoholism); clinical or derogatory, unlike the lighthearted 飲ん兵衛.
Standard kanji spelling with the colloquial ん insertion.
Kana-mixed spelling; common in casual writing.
Variant using 呑 (drink) instead of 飲; less common but seen.
Irregular okurigana usage; the ん is omitted in writing but pronunciation remains のんべえ.
Irregular okurigana variant with 呑; rarely used.
Search-only kanji form; not a standard spelling.
Derived from 飲む (to drink) with the colloquial ん insertion and 兵衛 (a common suffix in old male given names, used here as a personifying suffix). The exact origin is uncertain, but it likely arose as a playful nickname for a drinker.