a covered passageway with shops and stalls on either side
"We spent hours wandering through the historic arcade, stopping at every stall to buy souvenirs before heading back home."
A row of arches.
"The ancient Roman ruins featured a long arcade where people used to gather in the shade below the vaulted ceiling."
In plain English: An arcade is a place with rows of coin-operated video game machines where you play for fun.
"The family spent all afternoon playing games in the arcade before dinner."
Usage: In everyday usage, an arcade refers to a covered walkway lined with shops or entertainment venues like video game cabinets, rather than a structural row of arches. Use this meaning when describing a commercial street or a gaming area, while reserving the architectural definition for historical buildings and bridges.
To cover (something) as with a series of arches.
"The ancient library was once an arcade where sunlight streamed through the stone arches to illuminate the scrolls."
In plain English: To arcade is to play games in an old-fashioned machine with buttons and a screen.
"The old arcade game in the corner suddenly began to flicker and die."
Usage: Use the verb arcade only in rare architectural contexts to describe covering something with a continuous row of arches. In everyday conversation, do not use it as a synonym for walking through or playing in an arcade game.
The word entered English directly from the French term arcade, which originally described an arch or series of arches in architecture. It traces its roots back to the Italian arcata and the Latin arcus.