underdamped

/AH1 N D ER0 D AE1 M P T/
verb
  1. 1

    To fail to sufficiently suppress vibrations in.

adjective
  1. 1

    (of a linear dynamic system) Possessing a damping ratio between one and zero.

Source: https://en.wiktionary.org/wiki/underdamp, https://en.wiktionary.org/wiki/underdamped