A Discerner

is,

One who sees;
One who discovers;
One who knows and judges;
That which distinguishes;
or that which causes
to understand.

For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit,
and of the joints and marrow,
and is a discerner of the thoughts
and intents of the heart.

Hebrews 4:12