Is Brainiac a real word?

Is Brainiac a real word?

'Brainiac' is a blend of the words 'brain' and 'maniac'. It was originally the name of an extremely intelligent alien in the Superman comic strip. Definition and synonyms of brainiac from the online English dictionary from Macmillan Education. This is the British English definition of brainiac.

Is Brainiac an insult?

“Brainiac” has also, since the mid-1970s, come into use, often in a derogatory sense, as slang for someone perceived as very intelligent, roughly synonymous with “nerd.”