Latin studēre "to be diligent" ie, "to be pressing forward" (from the Proto-Indo-European root *(s)teu- "to push, stick, knock, beat") became studium "study, zeal" which was borrowed into English as study.
studium became Vulgar Latin *estudio, *estudiare, then Old French estuier "to keep, save", then estui "prison", then French étui. This was borrowed into English as étui or etwee, "small case for small articles". The plural étuis or etwees came to be thought of as a singular noun, spelled etweese. This became tweezer, and then was pluralized again as tweezers.
source: The American Heritage Dictionary of Indo-European Roots, Calvert Watkins, 2001
The Oxford Dictionary of English Etymology, 1991