Gavelock is a term that is primarily associated with locks that are used to secure canals and other waterways. However, when it comes to finding synonyms for this word, you'll find that there are a number of different options available. Some of the most common synonyms for gavelock include lock, gate, floodgate, sluice, dam, and barrier. While each of these words may have slightly different connotations or uses, they all share the same basic definition of a mechanism that is used to control the flow of water through a channel or waterway. Other possible synonyms might include latch, bolt, or fastener, depending on the specific context in which the word is being used.