closely and firmly; in a tight manner Her eyes were tightly closed. He held on tightly to her arm. a tightly packed crowd of tourists Which Word?tight / tightly Tight and tightly are both adverbs that come from the adjective tight. They have the same meaning, but tight is often used instead of tightly after a verb, especially in informal language, and in compounds:packed tight a tight-fitting lid. Before a past participle tightly is used:clusters of tightly packed flowers.