ἀῤῥαβώνarrhabṓn

a pledge, i.e. part of the purchase-money or property given in advance as security for the rest

Greek (New Testament) · G728

Meanings

an earnest, part payment in advance for security, a first instalment: 2 Corinthians 1:22, 2 Corinthians 5:5, Ephesians 1:14. (The word is found in classical Greek and was prob. brought to Greece by the Phœnicians (AR, Ephesians 1:14). It is found in π. with both spellings. In MGr. ἀρραβῶνα is an engagement ring; see MM, under that word)

Same root

עֲרָבוֹןʻărâbôwn · H6162a pawn (given as security)

Where it appears

Appears 3 times in the Bible.

2 Corinthians 1:22 and he has identified us as his own by placing the Holy Spirit in our hearts as the first installment that guarantees everything he has promised us.
2 Corinthians 5:5 God himself has prepared us for this, and as a guarantee he has given us his Holy Spirit.
Ephesians 1:14 The Spirit is God’s guarantee that he will give us the inheritance he promised and that he has purchased us to be his own people. He did this so we would praise and glorify him.

Source: G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), public domain.