スラックス
スラックス · surakkusu · JLPT N1 · noun
slacks
👖 スラックス sounds like 'slack'; slacks are the slack, relaxed trousers you wear at work.
Katakana スラックス comes from English 'slacks', loosened dress trousers. Remember: 'slack' pants are loose, not tight, so you wear them with a shirt.