from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The nail of the thumb.
- n. Computer Science A reduced image of a graphic or document page, used in order to view multiple images on a screen simultaneously or to download such images more rapidly.
- adj. Of, relating to, or of the size of a thumbnail.
- adj. Brief; cursory: a thumbnail biography.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The fingernail on the thumb.
- n. A rough sketch (e.g., the size of one's thumbnail).
- n. A small picture, used as a compact representation of a larger image.
- v. To describe concisely.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the nail of the thumb
thumb + nail. The phrase thumbnail sketch was first attested 1852. Verb sense attested 1930s. (Wiktionary)