shim

C1 · Advanced Countable noun Computing Technical

n. a small piece of software that helps an old program run on a new system by fixing compatibility issues.

n. a small library that transparently intercepts API calls and changes the arguments or handles the operation itself to provide compatibility.

“We had to install a shim so the old database software could talk to the new operating system.”

“The developers implemented a polyfill shim to ensure that modern JavaScript features would function correctly in legacy web browsers.”

C1 · Advanced Technical

v. to use thin pieces of material to make something level or fit perfectly.

v. to adjust, level, or align a mechanical assembly by the insertion of shims.

“You might need to shim the door frame if the wall isn't perfectly straight.”

“The installation crew spent hours shimming the heavy machinery to ensure it was perfectly level before bolting it to the concrete pad.”

C2 · Proficiency Countable noun Technical

n. a very thin device that criminals hide inside a credit card reader to steal information.

n. a paper-thin electronic device inserted into a card-reading slot to intercept data from the chip of a credit or debit card.

“The bank warned customers to check the ATM for a shim before inserting their cards.”

“Unlike bulky skimmers, a shim is thin enough to reside entirely inside the card slot, making it nearly impossible for a casual user to detect.”