From Latin + -ism.

Latinism (plural Latinisms)

1. Any word or phrase borrowed from Latin, or suggestive of Latin.
   • 2010, Ti Alkire, Carol Rosen, Romance Languages: a historical introduction page 325:

     [discussing numquam in the Old French portion of the Oaths of Strasbourg] a Latinizing spelling, maybe a pure Latinism, not surviving in modern French (but cf. Old French onques < umquam ‘ever’). Note the double negative, literally ‘will never make no pact’

• German: Latinismus
• Italian: latinismo
• Portuguese: latinismo
• Spanish: latinismo