semeion denotes a notable act or given indication that can prompt belief, identify something, or mark what is to occur.

The term most often denotes notable acts performed in public settings, frequently alongside wonders or powers; it also marks evidence sought from heaven and a given indication identifying a person, document, or coming event.

1. Notable acts performed publicly · dominant

   In Acts 4:16, the nominative singular names a notable act that had been performed and could not be denied. The plural also occurs for acts done through people: in Acts 14:3 the APB renders the clause that the Lord granted “that signs and wonders be done through their hands,” and in John 2:11 it calls one deed the first among Jesus' signs.

   Acts 4:16Acts 14:3Acts 5:12Acts 8:6John 2:11John 20:30
2. Evidence sought to validate a claim · common

   The accusative singular is the object of requests or demands in Mark 8:11, where opponents seek a sign from heaven in order to test Jesus. In John 6:30, the requested act is tied to seeing and believing, while Matthew 12:39 reports that a generation seeks such evidence but is offered only the sign of Jonah.

   Mark 8:11John 6:30Matthew 12:39Matthew 16:4Luke 11:16Luke 11:29
3. Given indication or identifying marker · occasional

   In Luke 2:12, the nominative singular introduces the specified circumstance by which the infant will be found. In 2 Thessalonians 3:17, the same form identifies Paul's handwritten salutation as the distinguishing mark in every letter; in Luke 11:30, Jonah is said to have become such an indication to the Ninevites.

   Luke 2:122 Thessalonians 3:17Luke 11:30
4. Marker of an impending event · occasional

   In Mark 13:4, the nominative singular is asked for as the indication of when the stated events are to be completed. Luke 21:7 similarly asks what the indication will be when these things are about to take place, and Luke 21:11 speaks of great signs from heaven alongside fearful sights.

   Mark 13:4Luke 21:7Luke 21:11

In the Anselm Project Bible: The APB generally presents the term with “sign” or “signs,” including performed acts, requests for evidence, and specified indications. In Acts 4:22 it expands the clause as “this sign of healing”; That wording does not by itself define the noun.