Strong's #804: asphales (pronounced as-fal-ace')

from 1 (as a negative particle) and sphallo (to "fail"); secure (literally or figuratively):--certain(-ty), safe, sure.

Thayer's Greek Lexicon:

̓́

asphalēs

1) firm (that which can be relied on)

2) certain, true

3) suited to confirm

Part of Speech: adjective

Relation: from G1 (as a negative particle) and sphallo (to "fail" )

Citing in TDNT: 1:506, 87

Usage:

This word is used 5 times:

 

Acts 21:34: "multitude: and when he could not know the certainty for"
Acts 22:30: "because he would have known the certainty wherefore he was accused of the"
Acts 25:26: "whom I have no certain thing to write unto my lord. Wherefore"
Philippians 3:1: "grievous, but for you it is safe."
Hebrews 6:19: "of the soul, both sure and steadfast, and which entereth"