Can it feel hunger, thirst, pain, sexual desire, fear, tiredness?
If yes to any of the previous: does it have agency to address and satisfy those feelings?
If yes to any of the previous: is it able to willingly delay instant gratification?
If yes: conscious.
If not: instincts-based being.
Note: you will find it challenging to agree on definitions of the words "feel", "satisfy", "willingly" and probably all the rest.