Vulgar slang for penis, used mainly by men and boys. Very informal; avoid in polite conversation.
Kantō dialect word for practice or rehearsal. Rare and regional; not standard Japanese.
The boys were laughing and saying 'dick'.
In parts of Kantō, they apparently call practice 'chinko'.
ペニス is a neutral, clinical loanword for the penis, while ちんこ is vulgar slang unsuitable for formal or medical contexts.
陰茎 is the formal anatomical term for the penis used in medical writing, whereas ちんこ is crude everyday slang.
ちんこ is the equally vulgar slang term for the penis, the male counterpart to まんこ for female genitalia.
おちんちん adds the polite/childish お- prefix and is used when talking to small children, whereas ちんこ is plain vulgar slang.
uvula
Hiragana spelling is standard for this colloquial word.
Katakana variant, often used for emphasis or in informal writing.
The origin is uncertain. Possibly related to the childish word ちんちん, with the suffix こ (small thing).