rebar

Etymology 1

Blend of reinforcing + bar

noun

1. (countable) A steel reinforcing bar in a reinforced concrete structure.
   The floor and walls for Copthall tunnel have already been constructed using formwork into which rebar (reinforcing bar) was placed, and then concrete poured. August 23 2023, Chris Howe, “Green screen: HS2's route through the shires”, in RAIL, number 990, page 35
2. (uncountable) A grid-shaped system of such bars.
   The hash mark of rebar or the curve of a hubcap will create curious shapes to be decoded; even, perhaps, entire subway trains and lengths of tracks will remain. 2020, David Farrier, “Thin Cities”, in Footprints, 4th Estate

verb

1. (transitive) To reinforce with bars of this kind.

Etymology 2

re- + bar

verb

1. (transitive) To bar again.
   After allowing the stranger to enter, she rebarred the door.
2. (music, transitive) To redistribute the notes of a musical score across the bars, e.g. when changing time signature.