Henry George Liddell, Robert Scott, A Greek-English Lexicon

A.guarded post, fort, castle, Hdt.5.52: esp. an outpost communicating with fortifications, Th.4.31,33,110, X.Cyr. 7.5.12: pl., guardrooms, Arist.Pol.1331a20.

2. safeguard, security, Pl.Lg.917b: preservative, D.6.24; amulet, Dsc.5.154, Plu. 2.378b, etc.; among the Jews φυλακτήρια were small rolls of parchment with texts from the Law written on them, bound to the forehead by persons praying, Ev.Matt.23.5; φ. χρυσᾶ, symbols denoting the kingdoms of Upper and Lower Egypt, OGI90.45 (Rosetta, ii B. C.); amulet, PMag.Lond.121.298 (pl.); metaph., “τὸ ὄνομά σου ἔχω ἓν φ. ἐν καρδίᾳ” PMag.Leid.W.18.2.

3. perh. guard or chain, PLond.ined.2199.