verb: To refill a hole with the material dug out of it.
verb: (archaeology) To refill an excavation unit to restore the former ground surface and/or to preserve the unit and make it recognizable as having been excavated.
verb: (US) To provide reserve support.
verb: (US) To replenish or restock due to attrition or loss.
verb: (gaming) To enter an online game that's already in progress, replacing a player who left early.
noun: The material that has been used to refill an excavation.
noun: (US) Reserve support personnel.
noun: (US) That which backfills; a replacement.
noun: (literature) Material in a story set earlier in the past, providing history or context for the current action.
