mindless

Concise Oxford English Dictionary © 2008 Oxford University Press:
mindless/ˈmʌɪndləs/

▶adjective

• 1 acting or done without justification and with no concern for the consequences.

  ■ (of an activity) simple and repetitive.

• 2 (mindless of) not thinking of or concerned about.

– derivatives
mindlessly adverb,
mindlessness noun.