The IUPAC convention for naming anions is:

Element root + ide

E.g. to make chloride, we take the root of the element chlorine, chlor-, and add the suffix, -ide.

Be careful, some roots are truncated if the adjacent vowels or vowel-sounding letters make the anionic name hard to say.

E.g. oxygen has the "y" removed and becomes oxide. Nitrogen has the "o" removed and becomes nitride.