nepho (3525), "to abstain from wine," is used metaphorically of moral "alertness," and translated "to watch," in the KJV of <2 Tim. 4:5>.
(from Vine's Expository Dictionary of Biblical Words)
(Copyright (C) 1985, Thomas Nelson Publishers)
of uncertain affinity: to abstain from wine (keep sober), i.e. (figuratively) be discreet:
KJV-- be sober, watch.