An antonym for overheard could be overlooked or ignored.
Yes, it is a form of the verb "to overhear" (to hear part of another conversation). It is the past tense and past participle of the verb, and may be used as an adjective (e.g. overheard secrets).
I accidentally overheard their private conversation while walking past their table at the restaurant.
There is no direct antonym for a thing that isn't there.
There is no antonym to pronoun.
The antonym for "transcribe" is "dictate".
Overheard
The duration of Overheard - film - is 1.65 hours.
I was scared when I overheard my mum and dad arguing.
Overheard - film - was created on 2009-07-30.
The couple whispered as they did not want to be overheard by the people sitting at the next table.
Synonyms for the word overheard: discovered, heard, recorded
Overheard - 2010 was released on: USA: 21 October 2010
To overhear someone or something means to hear speech between others. Overheard is the preterite and past participle of that verb."I overheard 'em! They're plotting to rob a bank."
Overheard
Calvin Coolidge's family spoke in sign language when they did not wish to be overheard
The antonym of the word 'synonym' is 'antonym'.
It is one word.