dictionary – el diccionario

(Pronounced deek-thyoh-nah-ryoh)

To remember that dictionary is pronounced deek-thyoh-nah-ryoh (gritar) in European Spanish, use the following mnemonic:

I checked in the dictionary for the correct word and declare my theory correct, that nasty man is a lothario (diccionario). 

Diccionario is masculine, so it's el diccionario. Imagine an elephant looking up the word trunk in a dictionary.