1. negligent As regards mental action, absorbed, abstracted, and preoccupied refer to the cause, absent or absent-minded to the effect. The man absorbed in one thing will appear absent in others. A Synonyms: abstracted, absent, heedless, listless, preoccupied, absent-minded, inattentive, negligent, thoughtless, absorbed, indifferent, oblivious Antonyms: alert, on hand, ready, wide-awake, attentive, prompt, thoughtful
Synonyms for negligent 
