Not energetic or diligent in performance; careless in performing duty or business; not complying with engagements at all, or not in due time; negligent; dilatory; slack.Wanting earnestness or activity; slow; relaxed; languid.Synonyms Neglectful, etc. (see negligent), careless, thoughtless, inattentive, slothful, backward, behindhand.n. An act of negligence.