underdetermined

/AH1 N D ER0 D T ER1 M AH0 N D/
verb
  1. 1

    To provide too few constraints to specify a unique solution.

adjective
  1. 1

    Having too few constraints to specify a unique solution.

Source: https://en.wiktionary.org/wiki/underdetermine, https://en.wiktionary.org/wiki/underdetermined