Usage: 2 forms in 4 verses
Form Translated As     In Verse(s)
πλατυσμώ an enlargement LXX.Ps.119.45
πλατυσμόν an enlargement LXX.2Sam.22.20LXX.Ps.18.19LXX.Ps.118.5

Liddell-Scott-Jones

πλατυσμός (platusmos) an enlargement G:N-M

πλατυσμός-μός, ,

widening, enlarging, dilatation, distension, [Refs 1st c.AD+]; ἐξήνεγκέ με εἰς πλατυσμόςμόν into broad space, into open ground, [LXX]; ἐν πλατυσμόςμῷ[LXX]

__II metaphorically, boasting, bragging, πουλυμαθημοσύνης [Refs]
__II.2 amplitude, τῆς ποιήσεως [Refs]

LSJ Scripture Refs: LXX.2Kgs.22.20