Wordnet 3.0
NOUN (2)
1. 
 a skilled worker who mounts pictures or jewels etc.; 
2. 
 someone who ascends on foot; 
- Example: "a solitary mounter of the staircase"[syn: mounter, climber]
The Collaborative International Dictionary of English v.0.48:
Mounter \Mount"er\, n.
   1. One who mounts.
      [1913 Webster]
   2. An animal mounted; a monture. [Obs.]
      [1913 Webster]
WordNet (r) 3.0 (2006):
mounter
    n 1: a skilled worker who mounts pictures or jewels etc.
    2: someone who ascends on foot; "a solitary mounter of the
       staircase" [syn: mounter, climber]