Romans 5:5 and hope doesn't disappoint us, because God's love has been poured out into our hearts through the Holy Spirit who was given to us. (WEB WEY NAS RSV NIV)

Psalms 17:13 Arise, O LORD, disappoint him, cast him down: deliver my soul from the wicked, which is thy sword: (KJV WBS)

Infallible (1 Occurrence)
... 2. (a.) Not liable to fail, deceive, or disappoint; indubitable; sure; certain;
as, infallible evidence; infallible success; an infallible remedy. ...
/i/infallible.htm - 7k

Fail (130 Occurrences)
... insolvent. 10. (vt) To be wanting to ; to be insufficient for; to disappoint;
to desert. 11. (vt) To miss of attaining; to lose. 12. ...
/f/fail.htm - 43k

False.
... promises. 3. (superl.) Not according with truth or reality; not true; fitted
or likely to deceive or disappoint; as, a false statement. 4 ...
/f/false..htm - 16k

Frustrate (7 Occurrences)
... 2. (vt) To bring to nothing; to prevent from attaining a purpose; to disappoint;
to defeat; to baffle; as, to frustrate a plan, design, or attempt; to ...
/f/frustrate.htm - 10k

Faithless (46 Occurrences)
... or a wife. 5. (a.) Serving to disappoint or deceive; delusive; unsatisfying.
Int. Standard Bible Encyclopedia. FAITHLESS. fath'-les ...
/f/faithless.htm - 20k

Disappears (4 Occurrences)

/d/disappears.htm - 7k

Destitute (25 Occurrences)
... 4. (vt) To make destitute; to cause to be in want; to deprive; -- followed by of.
5. (vt) To disappoint. Multi-Version Concordance Destitute (25 Occurrences). ...
/d/destitute.htm - 13k

Delude (2 Occurrences)
... to make a fool of. 2. (vt) To frustrate or disappoint. Multi-Version
Concordance Delude (2 Occurrences). Colossians 2:4 Now this ...
/d/delude.htm - 7k

Deceive (48 Occurrences)
... 1. (vt) To mislead; to cause to believe what is false, or disbelieve what is true;
to impose upon; to mislead; to cheat; to disappoint; to delude; to ensnare. ...
/d/deceive.htm - 22k