overextension

From over- + extension.

overextension (countable and uncountable, plural overextensions)

1. The state or quality of being overextended; extension beyond normal, correct, or appropriate bounds or limits.
   • 2009 February 13, David Brooks, “The Worst-Case Scenario”, in New York Times‎^[1]:

     Other nations sensed American overextension.

2. (linguistics) Application of a term to too many referents, as for example when a child uses cat to refer to all animals.

• underextension