Sunday is Word Day: "Thumb"

Thumb:
 [thuhm] tumere (Latin) "to swell," tumidus "swollen;" (see thigh) 
 
1. 1546 "All Thumbs": Awkward, clumsy; from saying, "When he should get aught, each finger is a thumb." 
2. 1580s "To be under someone's thumb": to be completely under someone's control.
3. 1690s "Rule of thumb": An old wives' tale alleges that this term is based on an old English law permitting men to beat their wives with a stick no bigger than a thumb. Snopes has since debunked this claim: "The phrase is almost certainly an allusion to the fact that the first joint an adult thumb measures roughly one inch, literally a rule (or ruler) of thumb. "

4. 1887 "Thumbs up" A signal which is said to derive from the Roman practice of deciding the fate of a fallen gladiator. It can also be linked coachmen who merely greet with their thumb so as to not release their reins.
5. 1906 "Thumbs down"
6. 1930s "Green fingers": Originated in England; a predecessor to...
7. 1940s "Green thumb": Etymologist Eric Partridge believes that this phrase is a variation of the old proverb: "An honest miller has a golden thumb.”  Millers being corn-grinders. (source here.)

Hasta la vista, wordsmiths. 
-s