The Collaborative International Dictionary of English v.0.48:

Mascot \Mas"cot\, Mascotte \Mas"cotte\, n. [Through French fr.
   Pr. mascot a little sorcerer or magician, mascotto
   witchcraft, sorcery.]
   1. A person who is supposed to bring good luck to the
      household to which he or she belongs.
      [1913 Webster]

   2. Hence: Anything that brings good luck; especially, an
      animal kept by a group, as a sports team, to serve as a
      symbol and to bring luck.
      [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

mascot
    n 1: a person or animal that is adopted by a team or other group
         as a symbolic figure

The Free On-line Dictionary of Computing (19 January 2023):

MASCOT

   Modular Approach to Software Construction Operation and Test:
   a method for software design aimed at real-time embedded
   systems from the Royal Signals and Research Establishment, UK.