- The grey-black sticky residue that forms around the perimeter of a band-aid that's been stuck to the skin for too long.Band-aid gruck often lingers after the band-aid has been removed, and it indicates where the band-aid once resided.
I have band-aid gruck on my knee because I left the band-aid on so long. It'll take days for it to wear off.
Dictionary of american slang with examples. .