According to the Internet Movie Database, the Lost in Space episode War of the Robots came out on February 9, 1966 and credits Robby the Robot as a robotoid and William Bramley and Ollie O'Toole as uncredited robotoid voice actors. A fansite Character Studies Analysis by Charles Mento claims Robot (Robby) "knows the term Robotoid". 20th Century Fox Home Entertainment describes the episode as "The family's robot is seemingly replaced when Will repairs a robotoid from an advanced civilization - until the new machine wreaks havoc by trying to take over the ship."

 And in April, 1968, Marvel Comics released Avengers #51 which introduced "The Robotoid".

Obviously, Beter didn't coin the term, but I think all of these references should be listed as being notable. -