What is Affirmant?

Legal Definition
Practice. One who makes affirmation instead of making oath that the evidence which he is about to give shall be the truth, as if he had been sworn. He is liable to all the pains and penalty of perjury, if he shall be guilty of wilfully and maliciously violating his affirmation.
-- Bouviers Law Dictionary
Legal Definition
A person who testifies on affirmation or who affirms instead of taking an oath. See Affirmation. Used in affidavits and depositions which are affirmed, instead of sworn to in place of the word "deponent."
-- Black's Law Dictionary
Legal Definition
One who affirms in lieu of swearing.
-- Ballentine's Law Dictionary