preposterous; absurd; outrageous
Almost exclusively used in the negative phrase 滅相もない (or めっそうもない), meaning 'don't be ridiculous' or 'that's out of the question'. The standalone adjective use is rare.
See also: 滅相もない (めっそうもない)
"I'll take responsibility." "Don't be ridiculous. This is my mistake."
I've never heard such an absurd story.
Kana spelling is common in everyday writing, especially in the set phrase めっそうもない.
Originally a Buddhist term, 滅相 denotes the aspect or mark of extinction in the sequence 生・住・異・滅. Its idiomatic use developed especially in 滅相もない, expressing that something is unthinkable or outrageous.