1. (astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions
   - terrestrial time, TT, terrestrial dynamical time, ephemeris time

Type of: time unit, unit of time

Encyclopedia: TDT

• sixty-six
• sixty-three
• sixty-two
• sizable
• sizar
• size
• size constancy
• size of it
• size stick
• size up
• sizeable
• sizeableness
• sized
• sizing
• sizz
• sizzle
• sizzler
• sizzling
• Sjaelland
• sjambok
• SK-Ampicillin
• ska
• skag
• Skagens Odde
• Skagerak