By this I mean, if I used a Latin phrase or used a Latin title for something, would that make sense? For example, I was thinking of using a Latin title for an in-world book. Or a Latin species scientific names. Or use the name of some kind of Latin title. Thanks,
Yes, if your world is in the right location. You specify medieval in the tags. (Edit: This question and answer were moved and the tags have changed)
Medieval Latin was the form of Latin used in Roman Catholic Western Europe during the Middle Ages. In this region it served as the primary written language, though local languages were also written to varying degrees. Latin functioned as the main medium of scholarly exchange, as the liturgical language of the Church, and as the working language of science, literature, law, and administration.
Medieval Latin represented a continuation of Classical Latin and Late Latin, with enhancements for new concepts as well as for the increasing integration of Christianity. Despite some meaningful differences from Classical Latin, Medieval writers did not regard it as a fundamentally different language. https://en.wikipedia.org/wiki/Medieval_Latin
This happens all the time in the Harry Potter books
Latin is good for this because it often makes sense to our ears - a lot of English words have Latin roots and if you understand a Romance language there will be more that makes sense.
The other aspect is that Latin was for a long time (and even now) the language of the learned especially as regards medicine. Latin makes things sound official. For example "prurigo nodularis", which means itchy bumps. You the dermatologist could tell someone they have itchy bumps but they might not feel they got their moneys worth since that is what they told when when you walked in. Pharmacy also uses a lot of Latin which always smells alchemical to me.
So: good precedent, less to make up, sounds official - you're good!