Am I wrong to get annoyed...

[TeaSleepInASproutFartHaze]

... at the word 'functionality'? My office working friends use it a lot and it annoys me intensely. Surely either something is functional or not. Things can't be just a bit functional therefore there is no state of 'functionality'. Don't get me started am management speak in general .

'Functionality' isn't recognized by the OED, so please hit them around the head with something large and heavy

I agree with you but it is in the Merriam-Webster online dictionary

However, M-W is descriptive and lets all sorts of horrors in!

I think people use it to mean 'capable of Doing Stuff' but want to sound big and clever.