Usage: 3 forms in 3 verses
Form Translated As     In Verse(s)
περίβολόν your enclosure LXX.Isa.54.12
περίβολοσ an enclosure LXX.Ezek.40.5
περίβολον their enclosure LXX.Ezek.42.20

Liddell-Scott-Jones

περίβολος (peribolos) an enclosure G:N-M

περίβολος, ον,

(περιβάλλω) compassing, encircling, στέφεα [Refs 5th c.BC+]

__II as substantive περίβολος, , ={περιβολή}, ἐχίδνης περίβολοι spires or coils of a serpent, [Refs 5th c.BC+], of a tomb, [Refs]: singular, enclosing wall, [Refs 5th c.BC+]; of a town wall, [Refs 5th c.BC+]; ἐν οἰκείῳ π. in a cage of his own, [Refs 5th c.BC+]; of the body as the case of the soul, [Refs]; wall of the heart, [Refs 5th c.BC+]
__II.2 area enclosed, enclosure, π. νεωρίων [Refs 5th c.BC+]; τῆς πόλεως π. [Refs 5th c.BC+]; of a temple, precinct, π. ἱεροῦ [LXX+1st c.AD+]; τῶν Ὡρῶν π. [Refs 1st c.AD+]
__III neuter, περίβολα πυρὶ φλεγόμενα fire-balls, [Refs 5th c.BC+]