abacus /abˈə-kəs/

1. A counting frame, consisting of horizontal rods along which movable beads can be slid
2. A level tablet on the capital of a column, supporting the entablature (architecture)

• trestle table
• trestle tables
• trestletree
• trestletrees
• trestlework
• trestleworks
• trests
• tret
• trets
• trevallies
• trevally
• trevis
• trevises
• treviss
• trevisses
• trew
• trews
• trewsman
• trewsmen
• trey
• trey-antler
• treybit
• treys
• trey-tine
• trez