- retrograde
[retrograde 词源字典]
- retrograde: see gradual
[retrograde etymology, retrograde origin, 英语词源] - retrograde (adj.)
- late 14c., originally of the apparent motions of planets, from Latin retrogradus "going back, going backward," from retrogradi "move backward," from retro- "backward" (see retro-) + gradi "to go, step" (see grade (n.)). General sense of "tending to revert" is recorded from 1530s.