I have, twice that I can remember.
- Nukamajig - microwave. I still use it from time to time because it’s too stupid not to.
- Miscombobulate - mixup and confuse. Just now, between the time it was and when the appartment building’s laundry room was closed for the night.
Happends to me all the time, more so since I got COVID. Especially embarrassing when public speaking. My foggy brain won’t come up with any invented word though
Fun fact: the average person loses 3 IQ points every time they get covid.