imponderable

Từ điển WordNet v3.1 - WordNet Dictionary

I - noun

a factor whose effects cannot be accurately assessed
- human behavior depends on many imponderables
• Hypernyms:
influence
• Hyponyms:
leaven, leavening

II - adjective

difficult or impossible to evaluate with precision
- such imponderable human factors as aesthetic sensibility
• Ant:
ponderable