Where does “[[čakati]], [[čekati]]” come from?

[[čakati]], [[čekati]] (Old Czech) comes from Proto-Slavic [[*čakati]], [[*čekati]].

Ancestry of “[[čakati]], [[čekati]]”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	[[čakati]], [[čekati]]	—

[[čakati]], [[čekati]] — Etymology, Origin & Word History | Etymology Explorer