There are many Latin expressions used in formal and written Spanish. Let’s learn some of them.

ad hoc – a propósito (for the purpose)
a fortiori – con mayor razón (with all the more reason)
ex aequo – con igual mérito (equally)
in extremis – en caso extremo (in an extreme case)
modus vivendi – arreglo entre dos o varias personas (arrangement, compromise)
non plus ultra – el tope (the absolute limit)
persona non grata – persona indeseable (unwelcome person)
sine qua non – imprescindible (essential condition)
a posteriori – después (after)
a priori – antes (before)
exabrupto – brusquedad (abrupt remark, outburst)
ex catedra – en tono magisterial (authoritatively)
ex profeso – expresamente (deliberately)
ex voto – ofrenda dedicada a Dios (offering to God)
(a) grosso modo – de forma general (in a general way)
ipso facto – inmediatamente; por el mismo hecho (immediately, by the very fact that)
(todo) quisque – todo el mundo (everybody and their uncle)
vox populi – voz popular (public opinion on something)

Nos vemos prontito.