Can you un-equip items?

[enricofermi2]

Are items permanent once used or can you un-equip them?

[AncientSpark]

You cannot unequip them by default. You can either spend 1 gold at shops to buy Item Removers or sell the unit (which will return the items to your inventory). There are also some event-only/perk-only items that unequip units as part of their effect.

[Jay Ren]

There is also (once unlocked) the combats that unequip all your items for the one battle.
But generally, the 1 gold item remover in the shops is your go to.