semi-erection; partial erection
Colloquial term for a penis that is not fully erect. Often used in casual or sexual contexts.
See also: 半勃起
In the morning, I went to the bathroom with a semi-erection.
He sent me a picture of his partial erection.
Abbreviation of 半勃起 (はんぼっき), combining 半 (half) and 勃ち, the noun form of 勃つ (to become erect).