There are a number of different synonyms for the word "clui," which is a French term that means "to close tightly" or "to tighten." Some possible synonyms for this term might include "shut," "seal," "clamp," "lock," "fasten," "secure," "zip," "button," "tie," or "cinch." Depending on the context and situation in which you are using this term, different synonyms may be more appropriate than others. For example, if you are talking about closing a door or cabinet, "shut" or "seal" might be more appropriate, while if you are talking about sealing a bag or container, "zip" or "cinch" might be more appropriate.