Just type "sps" on Alfred and a list of sysnonims (shall they are found) will be displayed. The user can preview (by clicking Shift) or can open the page in https://www.sinonimosonline.com/ with more detailed info about the synonym.
This is a Thesarurus for Spanish words. As there are not many (I couldn't find any) open APIs for thesaurus in Spanish, I used https://www.sinonimosonline.com/.
This worflow is based on Alfy https://github.com/sindresorhus/alfy.