'implausible excuse' is a correct and usable phrase in written English.
For example, you could use it in the sentence, "He provided an implausible excuse for his tardiness."
After around 1990, a "Gilligan's Island" couldn't exist without implausible excuses like poor reception or dead batteries.
Much of that scrutiny, though, involves finding implausible excuses for the incident, or digging up completely irrelevant dirt on Mr. Martin.
But even after the meeting, the police did not turn over any money, supplying instead what the mayor said were implausible excuses.
Early on, there were a few implausible excuses offered.
It's disappointing when Democrats offer implausible excuses for their votes, as Sen. Cory Booker and twelve other senators did this week.
On the implausible-excuse end of the spectrum: As for the irrelevant dirt: Michelle Goldberg of The Daily Beast compared "the way people talk about Martin and the way they talk about rape victims, whose clothes and histories are often subject to scrutiny no matter how cut-and-dried the case seems".
To be on board with "Prime Time Love," you've got to excuse a lot, as the show rests on the highly implausible premise that the Sanderses don't employ help.
It's as good an excuse as any for Dom et al to pull off the most outrageous and implausible string of road racing maybe in the history of mankind.
Not entirely implausible plots.
