godan verb (-mu), intransitive verb
get dressed up; dress up smartly
Implies putting on stylish or formal clothes, often for a special occasion. Can carry a slightly playful or self-conscious tone.
今夜のパーティーには洒落込んで行こう。
Let's get dressed up for tonight's party.
彼は一張羅のスーツで洒落込んだ。
He dressed up in his best suit.
godan verb (-mu), intransitive verb
treat oneself; splash out
Used when someone indulges in something nice, such as an expensive meal or a luxury experience, often with a lighthearted or self-indulgent nuance.
給料日だから、今夜は洒落込んで寿司でも食べよう。
It's payday, so let's treat ourselves to sushi tonight.
たまには洒落込んで高級ホテルに泊まるのもいい。
Once in a while, it's nice to splash out and stay at a luxury hotel.