The Czech term "thema" matches the English term "subject"

other czech words that include "thema" : english :
thema theme
thema topic
Czech Origins
One of the reasons why Czech was once called Bohemian is because it is thought that it originated in that area of the Czech Republic around the 9th century. One of the language’s earliest records referred to it as Proto-Czech.
Language of Administration
Czech began to spread beyond Bohemia after the 9th century because it was considered the language of administration. It started to appear in texts that covered law religious texts and writing. Prior to its spread, Czech was a relatively isolated language without a lot of outside influence so it remained comprehensive and unchained for a long period of time.
Words, Dialect, and Vowels
There are four different Czech Dialects that are present in different parts of the country. Common Czech is the most prevalently spoken, particularly in Bohemia. A lot of words in Czech contain no vowels at all. It’s possible for whole sentences to be composed without them. Words without vowels make Czech a tough language for people to learn.