What is Flee To The Wall?

Legal Definition
A metaphorical expression, used in connection with homicide done in self-defense, signifying the exhaustion of every possible means of escape or of averting the assault, before kllling the assailant.
-- Black's Law Dictionary
Legal Definition
Used in connection with killing in self-defense as meaning that one must do all in his power to avoid killing his assailant. See 96 Minn. 318, 2 L. R. A. (N. S.) 49, 104 N. W. 971.
-- Ballentine's Law Dictionary