inscrutable
adjective
UK/ɪnˈskruː.tə.bᵊl/
US/ɪnˈskruː.t̬ə.bᵊl/
Definitions of inscrutable adjective
Difficult to interpret or understand; mysterious and enigmatic.
She looked at him with an inscrutable gaze.
His inscrutable behavior puzzled everyone.
The details of the plan remain inscrutable.