Strong's G5441 · Greek

φύλαξ

phulax · foo'-lax

from 5442; a watcher or sentry

Scholarly Lexicons

Abbott-Smith Manual Greek Lexicon

 3 φύλαξ , -ακος, ὁ ( φυλάσσω ), [in LXX for שָׁמַר , צוּר ;] a guard, keeper : Ac 5:23 12:6 , 19 .† 

G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain