The best replacement for defined is undefined.

The best alternatives to defined are rated as following:
★★★★★  undefined
★★★  complex media
★★★  declared
★★★  exists
★★  exists perl
★★  ifdef
★  define php
★  define
★  object defined
  incentive defined
  defined
  predefined
  ill defined
  not well defined
  identified
  well defined
  well-defined

Your alternative for defined is not listed? Suggest!
Speaking about defined, one probably shouldn't forget about struct and union.

Other search terms related to defined and their ratings are:
★★★★★ struct and union
You have in mind a companion for defined and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of defined in all years. Click on graph for more.
defined
undefined
complex media