What does 俄 mean in Japanese?

sudden, abrupt, unexpected, immediate, hasty, improvised

俄 (Niwaka) — sudden · Japanese Dictionary

にわか

Niwaka

Usually written in kana.

Other forms: 俄か、仁輪加

俄 (Niwaka) is a Japanese na-adjective meaning “sudden, abrupt, unexpected, immediate”.

na-adjective, adjectival nounsudden; abrupt; unexpected; immediate; hasty; improvised
nounimpromptu skitsometimes written as 仁輪加
nounbandwagon fan; fair-weather fan

にわか仕込みの知識ではその問題は解けなかった。
Hastily acquired knowledge was not enough to solve the problem.

Sentences from Tatoeba (CC BY 2.0 FR).