Classic reading: The same as the two of Clubs (trusted friend), unless it is the significator. Generic: the ring and marriage (Cupid and Venus's two of diamonds).
General meaning
Upright
ringmarriagetrusted friendbondcommitment
↕ Reversed: Commitment in doubt, doubtful friend.
By topic
Love
engagementringmarriagecouplepromise
Friendship
trusted friendallypactfaithfulnessconfidant
Family
marriagecouplecommitmentbondfamily alliance
Career
professional alliancetrusted mentorcontractpartnerbacking