Cyrillic slovo writes the same consonant, holds the same place and takes the same numeral, two hundred. The agreement between the two systems that began at the previous letter continues here, and the name is identical in both scripts, the same Slavonic noun for word.
This is therefore the closest the two alphabets come to being the same letter in everything but appearance. Sound, position, name, sense and number all coincide. What does not coincide is the shape, and this letter is one of the places where that fact is at its starkest, because the Cyrillic form is a Greek sigma with almost no alteration and the Glagolitic form resembles no Greek letter at all.
The name carries a theological charge in both traditions equally. The Slavonic translation of the opening of John begins with this word, and the alphabet that was made for that translation names a letter with it, so the recitation of the alphabet and the opening of the gospel share a word in a way that the Greek alphabet's letter names, which are inherited labels with no sense in Greek, never could. That is a genuine difference between the Slavonic letter names and the Greek ones, and it does not depend on any particular reading of the recitation as a whole.