Conjunction

1. or even, or more like, or should I say

   His face was dirty, nay filthy.

   • 1748. David Hume. Enquiries concerning the human understanding and concerning the principles of moral. London: Oxford University Press, 1973. § 18.

     And even in our wildest and most wandering reveries, nay in our very dreams, we shall find, if we reflect, that the imagination ran not altogether at adventures,

Noun

1. A vote against.

   I vote nay, even though the motion is popular, because I would rather be right than popular.

2. A person who voted against.

   The vote is 4 in favor and 20 opposed, the nays have it.