Since there’s no letter J in Ukrainian, today is the first of four wildcard days. I decided to do Polish names because part of Ukraine was Polish territory for many centuries, and a lot of upper-class Ukrainians became very Polonified. Thus, there’s a plausible connection between Ukrainian and Polish names.
Male names:
Jaromir means “fierce peace” and “fierce world.”
Jarzysław means “glowing glory.”
Jasnomir means “bright peace” and “bright world.”
Jasnosław means “bright glory.”
Jozafat is a rare name which comes from Hebrew name Yehoshafat (God has judged). Jozafat Kuncewicz (ca. 1580–1623) was a Polish-Lithuanian monk and archbishop who tried to reconcile Catholics and Orthodox Christians. He was stoned to death by an angry mob, and was sainted in 1867.
Juwentyn comes from Roman name Iuventinus, which may be related to Iuvenalis (Juvenal), meaning “youthful.”
Female names:
Janisława possibly means “John’s glory.” This, and the male form Janisław, seem to be newly-coined names in the Slavic languages. They also occur in Bulgarian, Slovenian, and Croatian.
Januaria comes from Roman cognomen Ianuarius (January), ultimately derived from Ianus (Janus) (archway).
Jaroslava means “glory of light.”
Jowita is a feminine form of the Roman name Iovita, derived from Iovis (Jove) and the stem of Iuppiter (Jupiter). It ultimately comes from the Indo–European root *Dyew-pater; Dyews means Zeus, and pater is father. In turn, Zeus derives from root *dyew- (“sky” or “shine”).
Judyta is the Polish form of Judith, which comes from Hebrew name Yehudit (Jewish woman; woman from Judea).
Justyna is the Polish form of Justine, which ultimately derives from Latin name Iustus (just).
Onomastics Outside the Box 
It’s fun to learn what names means and where they originate from .
Stopping in from A to Z: https://brewingcoffeetwistingwordsbreakingpencils.ca/2022/04/12/jog/
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