Definition of mighty work in US English:

mighty work

noun

  • A miracle (usually in plural); (also, less specifically) in plural, God's works of creation, redemption, etc.

Origin

Mid 16th century; earliest use found in The Holie Bible, conteynyng the Olde Testament and the Newe. After ancient Greek δύναμις (as used in Hellenistic Greek in the New Testament, usually in plural δυνάμεις).