Bhagavad Gita, Chapter 18, Verse 25

That action is declared to be Tâmasika which is undertaken through delusion, without heed to the consequence, loss of power and wealth, injury to others and one's own ability.

Real recklessness is named here directly, acting without any real thought to consequence or ability.

Krishna lists exactly what's missing, self-awareness, foresight, concern for others, rather than leaving the failure vague. Real carelessness defines this lowest mode of action.