Definify.com
Webster 1913 Edition
Understander
Unˊder-stand′er
(ŭnˊdẽr-stănd′ẽr)
, Noun.
 One who understands, or knows by experience. 
[R.] 
Dryden.
 Webster 1828 Edition
Understander
UNDERSTAND'ER
,Noun.
  Definition 2025
understander
understander
English
Noun
understander (plural understanders)
-  One who understands something.
-  1955, Rex Stout, "Die Like a Dog", in Three Witnesses, October 1994 Bantam edition, ISBN 0553249592, page 166:
- "You knew Mr. Kampf intimately?"
- "Yes, I guess so." She smiled as one understander to another.