Abbott-Smith Manual Greek Lexicon
φυλακτήριον (G5440)
1 * φυλακτήριον , -ου, τό an outpost, fortification (Thuc., al.). a safeguard (Plat.). an amulet (Plut., al.); in NT for the Talmudic תְּפִלִּין, a prayer fillet, a phylactery , a small strip of parchment on which portions of the law were written and worn on the forehead and next the heart (cf. Ex 13:16 ): Mt 23:5 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain