The story
From inkhorn + term, so coined for their increased usage of ink from their length (i.e. one would need to dip their quill into the inkhorn multiple times in order to completely write the word out).
Etymology from Wiktionary, CC BY-SA 4.0.
inkhorn term
Today it means: A borrowing from another language thought to be pretentious or unneeded, especially from Latin or Greek. Full definition →