Where does “Cejka” come from?

Cejka (English) comes from Czech čejka, from Proto-Slavic čajьka, from Proto-Slavic -ьka, from Proto-Balto-Slavic -ikaʔ, from Proto-Indo-European -ikeh₂.

Ancestry of “Cejka”, step by step

Step	Language	Word	Meaning
1	Czech	čejka	lapwing
2	Proto-Slavic	čajьka	gull
3	Proto-Slavic	-ьka	—
4	Proto-Balto-Slavic	-ikaʔ	—
5	Proto-Indo-European	-ikeh₂	—

Every word from Proto-Indo-European -ikeh₂ →Every word from Proto-Slavic -ьka →Every word from Proto-Slavic čajьka →