noun, plural co·sig·na·to·ries. a person who signs a document jointly with another or others; cosigner.

What does Hydrothermic mean?

hy·dro·ther·mal

(hī′drə-thûr′məl) 1. Relating to hot water, especially water heated by the Earth's internal heat.

What does YÆ mean?

1 : affirmation, assent. 2a : an affirmative vote. b : a person casting a yea vote.