Strong's Concordance H651

Original Word: אָפֵל
Transliteration: ʼâphêl
Phonetic Spelling: aw-fale'
from an unused root meaning to set as the sun; dusky; very dark.

Usages throughout the bible

Amos 5:20 - Shall not the day of the LORD be darkness, and not light? even very dark, H651 and no brightness in it?