An adverb expressing smooth, gliding motion or effortless movement — used for things slipping off, passing through easily, or processes proceeding without trouble.
手袋がスルッと滑って落ちた。
The glove slipped off smoothly.
彼は人混みの間をスルッと抜けていった。
He slipped through the crowd.
この鍵はスルッと回って、簡単に開錠できた。
This key turned smoothly and unlocked it easily.