An onomatopoeic adverb meaning tightly or firmly — used for actions like holding, squeezing, gripping, or hugging strongly.
母親は赤ちゃんをぎゅっと抱きしめた。
The mother hugged the baby tightly.
怖くて彼はハンドルをぎゅっと握った。
He gripped the steering wheel tightly because he was scared.
荷物が崩れないように、紐でぎゅっと縛った。
I tied the luggage tightly with rope so it wouldn't fall apart.