Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
It's also possible that these Doctors are the elder versions of the Doctor that have popped up, and possibly even explain the appearance of Tom Baker's The Curator in the 50th-anniversary special, "The Day of the Doctor."
Source: https://comicbook.com/tv-shows/news/doctor-who-special-3-the-giggle-watch-bigeneration/