Strong's G5069 · Greek

τετράδιον

tetradion · tet-rad'-ee-on

neuter of a presumed derivative of tetras (a tetrad; from 5064); a quaternion or squad (picket) of four Roman soldiers

Scholarly Lexicons

Abbott-Smith Manual Greek Lexicon

 1 † τετράδιον , ου, τό a quarternion, a group of four : στρατιωτῶν , Ac 12:4 (Philo). 

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