Luke 23:38 And a superscription also was written over him in letters of Greek, and Latin, and Hebrew, THIS IS THE KING OF THE JEWS. [kjv]
ην δε και επιγραφη επ αυτω ο βασιλευς των ιουδαιων ουτος [gnt]
Note that while the Latin Vulgate says the title is in "
latinis" (i.e., Latin), the Greek uses the word «
ρωμαϊκούς» which is, literally, the "
Roman" language.
Note that the Greek does not include the word for "
letters" which would be inferred. The Greek just says that the "
inscription" was "
written" or "
inscribed".
Note here that the Greek word for "
title" as «
τίτλων» is a Latin word, "
titulum". From the Latin word "
titlon" comes the English word "
title".
Again, the Greek word for "
Latin" here is «
ρωμαϊστή» or, literally, the language of the "
Romans".
The Latin word
"litterae" ≈ "letter" from which we get the English word "
literally" as in the phrase "
the letter of the law" and the word "
literate", "
literature", etc.