Scratch
Another word for addition which starts with the letter N is New.
letter
Another word for water that starts with the letter 'O' is oxygen dihydrogen.
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Atop.
advertise
astamp
Astonishing.
Amazing
Orator is another word for speaker.
"Deceiver" is another word for liar that starts with the letter A.
Authority can be used as another word for expert and starts with an "A". Example: An authority on the subject of crime, notes that...