The term lower mast refers to the part of a ship's mast that is located closer to the deck. There are several synonyms for this nautical term that can be used in different contexts. One common alternative is the term "lower section," which refers to the part of the mast that is below a specific point, such as the cross trees or trestle trees. Other synonyms for lower mast include "mainmast," which is the tallest and most central mast on a ship, and "foremast," which is located at the front of the ship. Additionally, the term "base," "foot," or "butt" can be used to refer to the lower part of any mast.