THUMBNAIL
thumbnail
(noun) the nail of the thumb
Source: WordNet® 3.1
Etymology
Noun
thumbnail (plural thumbnails)
The fingernail on the thumb.
A rough sketch (e.g, the size of one's thumbnail).
(chiefly, computing) A small picture, used as a compact representation of a larger image.
Usage notes
• (computing): Unlike an icon, which is generally a representative symbol, a thumbnail is a smaller identical copy of the original larger image.
Verb
thumbnail (third-person singular simple present thumbnails, present participle thumbnailing, simple past and past participle thumbnailed)
(transitive) To describe concisely.
(transitive, computing) To create a smaller representation of (a larger image).
Source: Wiktionary