Definitions:

1. A monumental structure, often found in architecture, sheped like a freestanding archway through which one may walk, intended to commemorate an important event, victory or honor a significant individual. NOUN
   • Ancient Rome is renowned for its triumphant arches, which were build to honor the emperors and their military conquests.
2. A monumental structure, often freestanding, that features one or more arched passageways, typically constructed to commemorate a significant event, or to honor a distinguished person. NOUN
   • The Arc de Triomphe in Paris is one of the most famous triumphal arches in the world.

Synonyms:

• commemorative arch
• honorific arch
• memorial arch
• monumental arch
• victory arch