Strong's G2178 — ἐφάπαξ (adverb)
ephapax (ef-ap'-ax) adv.
1. upon one occasion (only)
[from G1909 and G530]
KJV: (at) once (for all) 
Root(s): G1909, G530 
Hebrew root: ἅπαξ
Occurrences: 5