thumbnail

Meanings

1. The fingernail on the thumb.
2. A rough sketch (e.g., the size of one's thumbnail).
3. A small picture, used as a compact representation of a larger image.
4. A picture displayed by posts and videos pre-clicked conveying the matters discussed/shown in that post.

1. To describe concisely.
2. To create a smaller representation of (a larger image).

Etymology

From thumb + nail. Compare West Frisian tommeneil (“thumbnail”), Dutch duimnagel (“thumbnail”), German Daumennagel (“thumbnail”). The phrase thumbnail sketch was first attested 1852. Verb sense attested 1930s.