Replying to the poll question: I usually ignore them if I can understand them in their context.
But I may check them up if the context is unclear or if they appear repeatedly.
That said it sometimes happens that unusual English words have Latin roots, so they translate quite easily into Spanish.
Paliativo (noun or adjective) and
paliar (verb) are common words in Spanish - so palliating just makes perfect sense to me even though I may have never heard it in English.
Same with
plebeyo (plebian),
obscurantismo (obscurantism),
derogación (derogation).
Ignis fatuus and
lasciva puella are plain Latin.
The first one translates into Spanish literally (
fuego fatuo).
In the second one the adjective has not changed, while the noun is very well known - it was easy for simple sentences such as "Ubi est parva puella?"
Definetely Latin is a must
