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; 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/.