The Collaborative International Dictionary of English v.0.48:

Montaigne \Mon"taigne\, n.
   A mountain. [Obs.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

Montaigne
    n 1: French writer regarded as the originator of the modern
         essay (1533-1592) [syn: Montaigne, Michel Montaigne,
         Michel Eyquem Montaigne]