The Collaborative International Dictionary of English v.0.48:

Mangler \Man"gler\, n. [See 1st Mangle.]
   One who mangles or tears in cutting; one who mutilates any
   work in doing it.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mangler \Man"gler\, n. [See 3d Mangle.]
   One who smooths with a mangle.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mangler
    n 1: a person who mutilates or destroys or disfigures or
         cripples [syn: mutilator, maimer, mangler]

The Jargon File (version 4.4.7, 29 Dec 2003):

mangler
 n.

    [DEC] A manager. Compare management. Note that system mangler is
    somewhat different in connotation.


The Free On-line Dictionary of Computing (30 December 2018):

mangler

   [DEC] A manager.  Compare mango; see also management.
   Note that system mangler is somewhat different in
   connotation.

   [Jargon File]