Sentence:  In the ancient world, Greek was written in a script that was <WSD>unicameral</WSD> and atonic. It consisted of a single set of forms – the ones we now regard as upper case. There was little or no punctuation, and there were no diacritics. 
Meaning of the word marked with <WSD> tags:  Of a script or typeface: making no distinction between upper and lower case, but rather having only one case. Mkhedruli inscription from (Mount Athos). It is unicameral – it does not distinguish between upper and lower case.