| 1 | Sanskrit | ऋत | met with, afflicted by; proper, right, fit, apt,... |
| 2 | Sanskrit | ऋतु | any settled point of time, fixed time, time... |
| 3 | Proto-Indo-Iranian | Hr̥túš | fixed point of time, period, epoch; fixed order,... |
| 4 | Proto-Indo-European | h₂ér-tus ~ h₂r̥-téw-s | — |
| 5 | Proto-Indo-European | h₂er- | to fit, to fix, to put together |