The only accurate term for a robot containing twelve letters would be a bionic person.
robot
robot
Robot is not a compound word.
Cyborg
Successfully is a 12 letter word with three set of double letters. Stubbornness is another 12 letter word.
Brown recluse is a 12-letter word for a type of spider.
The word robot is from Czech. In Czech robot means "work".
There are many such words. One would be DETER. Another is REFER. And still another is ROBOT.
Lighthearted is a 12 letter word. Lithographed is another 12 letter word that starts with L and ends with D.
manufactured
manufactured
Robot - Doctor Who - happened on 1974-12-28.