Therate is not as commonly used as other words, but it does have a few synonyms worth exploring. One of them is "ensheathed", which means covered or enclosed in a sheath-like structure. Another synonym is "sheathe", which refers to the act of placing something into a protective covering. One could also use "encased", which implies that something is completely enclosed in a casing or covering. Lastly, "shrouded" can be used, suggesting that something is wrapped or hidden. Although the word "thecate" may not be widely recognized, these synonyms offer alternative options to describe a similar concept.