The best replacement for gross negligence is negligence.

The best alternatives to gross negligence are rated as following:
★★★★★  negligence
★★★  willful misconduct
★★  ordinary negligence
★★  recklessness
★★  simple negligence
★  malpractice
★  criminal negligence
★  sole negligence
★  wilful default
★  willful negligence
★  misconduct
★  wilful misconduct
  bad faith
  intent
  mere negligence
  willful

Your alternative for gross negligence is not listed? Suggest!
Speaking about gross negligence, one probably shouldn't forget about vehicular manslaughter.

Other search terms related to gross negligence and their ratings are:
★★★★★ vehicular manslaughter
You have in mind a companion for gross negligence and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of gross negligence in all years. Click on graph for more.
gross negligence
negligence
willful misconduct