Synonyms:
imponderable
Meaning: difficult or impossible to evaluate with precision; "such imponderable human factors as aesthetic sensibility"
noun
meaning of the word
Synonyms:
imponderable
Meaning: a factor whose effects cannot be accurately assessed; "human behavior depends on many imponderables"
Usage examples
Invisible, imponderable, quickening with vigorous motion, slackening in rest and sleep, passing quite away in death, it is the most obvious sign of life.