N-butyllithium is a chemical compound that is commonly used in organic chemistry as a strong base and as a reagent for nucleophilic addition reactions. However, there are a few synonyms that can be used to refer to this compound, including butyllithium, BuLi, and lithium butyl. These synonyms are often used interchangeably, but it is important to note that they all refer to the same compound. Additionally, it is important to handle n-butyllithium with extreme caution, as it is highly reactive and can be very dangerous if mishandled. As such, it should only be used by trained professionals with appropriate safety equipment and protocols in place.