1. "Skin" + "-y" suffix: The most likely origin is that "skinny" is a combination of "skin" and the adjective-forming suffix "-y." This suggests a meaning of "having little flesh, being close to the skin."
2. Scandinavian influence: Some linguists believe the word may have come from Old Norse "skinn", meaning "skin." This would support the "skin" + "-y" theory.
3. Old English origin: Another possibility is that "skinny" comes from Old English "scinn" or "skinne," which also meant "skin."
4. "Skin" + "knee": This is a less likely explanation, but some believe "skinny" might have originated from a combination of "skin" and "knee," referring to the way thin limbs resemble knees.
Overall: While the exact origin is debated, it's clear that "skinny" has a strong connection to the concept of "skin" and a lack of flesh.