次第 しだい
shidaini

Adverb

1. gradually; by degrees; little by little; bit by bit

つにつれて、天気 てんき次第 しだい悪化 あっかしつつあった。
higa tatsuni tsurete tenkiwa shidaini akka shitsutsu atta.
The weather was getting worse and worse as the day went on.