  The low-energy theory of hybrid nanowire systems fails to define Majorana
fermion (MF) in the strong tunneling and magnetic field strength. To address
this limitation, we propose a holistic approach to define MF in which the
quasi-excitation in nanowire and superconductor constitutes together its own
``antiparticles''. This definition is general, beyond the constraint presented
in the low-energy theory. It reveals that the Majorana phase depends not only
on the chemical potential and Zeeman energy in nanowire but also on those of
superconductor, and that the mismatch of chemical potential leads not to
observe MF. Such a broader perspective provides more specific experimental
guidance under various conditions
