Where does “круглосуточный” come from?

круглосуточный (Russian) comes from Russian кру́глый, from Proto-Slavic krǫglъ, from Proto-Slavic krǫgъ, from Proto-Indo-European krongʰ-o-, from Proto-Indo-European (s)ker-, from Proto-Indo-European sek- — to cut, cut off, sever.

круглосуточный (Russian): around-the-clock, round-the-clock

Definitions

  1. around-the-clock, round-the-clock

Ancestry of “круглосуточный”, step by step

круглосуточный traces back through two separate lines of ancestry.

via Russian кру́глый

StepLanguageWordMeaning
1Russianкру́глыйround, circular
2Proto-Slavickrǫglъround
3Proto-Slavickrǫgъcircle
4Proto-Indo-Europeankrongʰ-o-—
5Proto-Indo-European(s)ker-to cut off; to turn, bend
6Proto-Indo-Europeansek-to cut, cut off, sever

via Russian су́тки

StepLanguageWordMeaning
1Russianсу́тки24 hours (of the clock), day, day and night, nychthemeron
Every word from Proto-Indo-European sek- →Every word from Proto-Indo-European (s)ker- →Every word from Proto-Indo-European krongʰ-o- →