serdab /sər-däbˈ/

1. An underground chamber
2. A secret chamber in an ancient Egyptian tomb

• first-attack
• first-begotten
• first blood
• first blush
• First Book of Discipline
• first-born
• first cab off the rank
• first catch your hare
• first cause
• first chop
• first-class
• first-class mail
• first-class post
• first cousin
• first cousin once removed
• first-day
• first-day cover
• first-day covers
• hexaëmeron
• hexed
• hexene
• hexenes
• hexes
• hexing
• hexings