Where does “catchword” come from?

I need to work through this etymology chain carefully. The chain provided is: English catchword → English worth → Middle English worth → Proto-Germanic wurdą → Latin captio → Latin capio → Latin ago → Latin ago This chain has serious problems. It shows "Latin ago" appearing twice at the end, and the progression doesn't make linguistic sense (Proto-Germanic wurdą wouldn't derive from Latin; Latin words don't typically precede Germanic ones in a descendancy chain; and "worth" has no etymological connection to "ago" or "capio"). However, my instructions are to "State only what the chain supports. Do not invent dates, cognates, or intermediate steps." The chain as given is incoherent and appears to be an error in the source material. Following the rule strictly—only stating what the chain supports—I cannot construct a reliable one-sentence summary because the chain itself is contradictory and lingu

catchword (English): A word under the right-hand side of the last line...