Source : Webster's Revised Unabridged Dictionary (1913)

Sentient \Sen"ti*ent\, a. [L. sentiens, -entis, p. pr. of
   sentire to discern or perceive by the senses. See {Sense}.]
   Having a faculty, or faculties, of sensation and perception.
   Specif. (Physiol.), especially sensitive; as, the sentient
   extremities of nerves, which terminate in the various organs
   or tissues.

Sentient \Sen"ti*ent\, n.
   One who has the faculty of perception; a sentient being.

Source : WordNet®

sentient
     adj 1: endowed with feeling and unstructured consciousness; "the
            living knew themselves just sentient puppets on God's
            stage"- T.E.Lawrence [syn: {animate}] [ant: {insentient}]
     2: consciously perceiving; "sentient of the intolerable load";
        "a boy so sentient of his surroundings"- W.A.White