一層 (Issou) is a Japanese adverb meaning “even more, still more, all the more, more than ever”.
Meanings
- adverbeven more; still more; all the more; more than ever
- nounone layer
- nounlowest floor (of a building)
- adverbrather; sooner; preferably
Examples
今日はいっそう寒い。
It is still colder today.
彼は事態を一層悪くした。
He added insult to injury.
雨はいっそう激しくなった。
The rain fell even harder.
Sentences from Tatoeba (CC BY 2.0 FR).