"Mortify" means "put to death." "They that are Christ's have crucified the flesh with the affections and lusts" (Galatians 5:24).

Source:

KJV Defenders Study Bible, by Dr. Henry Morris, Ph.D.
Publisher: Thomas Nelson
Language: English
DEF 10 ISBN 0-529-10444-x
DEF 10-1 ISBN 0-529-10445-8