Translation guide
Describes the physiological state of having an erect penis. Japanese has several expressions ranging from clinical to slang, and the appropriate choice depends heavily on context and politeness level.
Noun meaning 'erection'. Often used in compound phrases or medical descriptions.
朝勃起は健康の証です。
Morning erections are a sign of health.
To talk about having an erection in very informal, often male-oriented settings.
Literally 'is standing'. A common euphemism among men. Context makes the meaning clear.
朝からずっと立ってるんだけど。
I've had an erection since morning.
Slang implying a very hard, rigid erection. Often used in a boastful or humorous way.
彼女を見たらギンギンになった。
I got rock hard when I saw her.
Describes a state of being horny, which often implies having an erection. More about the feeling of arousal than the physical state itself.
ムラムラして眠れない。
I'm too horny to sleep.
To refer to an erection indirectly, often in mixed company or more polite contexts.
Literally 'is energetic/healthy'. A playful euphemism, often used for morning erections or when talking to a partner.
朝から元気だね。
You're full of energy this morning. (implying an erection)
Literally 'is reacting'. A more indirect way to say the body is responding sexually.
体が反応している。
My body is reacting. (implying an erection)
To describe an erection in a formal medical or scientific context.
Formal clinical phrase: 'the penis is erect'. Used in medical documents or doctor-patient conversations.
患者は陰茎が勃起していると訴えた。
The patient complained that his penis was erect.
Medical term for erectile dysfunction (ED).
勃起不全の治療薬。
Medication for erectile dysfunction.
The English phrase 'have an erection' does not translate directly into a single Japanese verb. Using エレクションを持つ is unnatural. Stick to the expressions above.
勃起 is the standard term and can be used in most situations, while 立つ is casual male slang. Use 勃起 when in doubt, but be aware that in very formal settings, even 勃起 might be too direct; euphemisms are preferred.