The Collaborative International Dictionary of English v.0.48:

Terminator \Ter"mi*na`tor\, n. [L., he who limits or sets
   bounds.]
   1. One who, or that which, terminates.
      [1913 Webster]

   2. (Astron.) The dividing line between the illuminated and
      the unilluminated part of the moon.
      [1913 Webster]
      [1913 Webster]

WordNet (r) 3.0 (2006):

terminator
    n 1: someone who exterminates (especially someone whose
         occupation is the extermination of troublesome rodents and
         insects) [syn: exterminator, terminator, eradicator]

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

terminator

    A resistor connected to a signal wire in a bus
   or network for the purpose of impedance matching to prevent
   reflections.

   For example, a 50 ohm resistor connected across the end of an
   Ethernet cable.  SCSI chains and some LocalTalk wiring
   schemes also require terminators.

   (1995-05-17)