The answers to the clues below will have something in common.

1. Cadence

2. A religious song 

3. Mythological maiden

4. Romantic rendezvous 

5. One of the gifts of the Magi

6. A chamber wholly or partly underground 

7. The nearly straight-line configuration of three celestial bodies

 

Answers:

 

1. RHYTHM

2. HYMN

3. NYMPH

4. TRYST

5. MYRRH

6. CRYPT

7. SYZYGY - - - Words that have only Y as a vowel