The company name originated as an acronym for the phrase “W l’Italia liberata eredenta”, where the W is an abbreviation for "Viva!" (Long live Italy, liberated and redeemed). Triestina comes from the name of the city of Trieste. When Wilier was founded Trieste was not part of Italy and the name 'Wilier Triestina' reflected a patriotic desire for it to be rejoined.
According to Wilier Triestina's US company website, the proper pronunciation of their name is /Vee’-lee-air Tree-es-tee’-na/.