Derogatory term for someone who lives off others, especially an adult who depends on parents for financial support. The literal image is 'shin gnawer', suggesting a pest that clings and feeds.
He's still a freeloader living off his parents even at thirty.
I can't keep being a sponger forever.
Usually written in kana; the kanji forms are rare and It is usually written in kana.
Rare kanji form; 脛 means shin and 齧り means gnawing, reflecting the literal image.
Katakana variant sometimes seen in casual writing.
Rare kanji form using 臑, a variant of 脛.
From 脛 (すね, shin) + かじり (齧り, gnawing), literally 'shin gnawer'. The image is of a small animal or pest clinging to someone's leg and gnawing, metaphorically extended to a person who lives off others.