This is the 10138th most frequent Russian word.
безответственно
Irresponsibly.
The adverb 'безответственно' here describes the action of behaving, indicating irresponsibility and lack of care in professional duties.
Он вел себя безответственно на работе.
He behaved irresponsibly at work.
The adjective form 'безответственным' characterizes the action, demonstrating carelessness or neglect.
Ее поступок был абсолютно безответственным.
Her action was absolutely irresponsible.
Here, 'безответственно' as an adverb explains the nature of the decision-making process, emphasizing the imprudence involved.