We don't have synonyms for boult yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are bolt, bout and moult.
(v) :
Alternative form of bolt (“to sift”). [(transitive) To connect or assemble pieces using a bolt.]
(n) :
Obsolete form of bolt. [A (usually) metal fastener consisting of a cylindrical body that is threaded, with a larger head on one end. It can be inserted into an unthreaded hole up to the head, with a nut then threaded on the other end; a heavy machine screw.]
(v) :
Alternative form of bolt (“to sift”). [(transitive) To connect or assemble pieces using a bolt.]
(n) :
Obsolete form of bolt. [A (usually) metal fastener consisting of a cylindrical body that is threaded, with a larger head on one end. It can be inserted into an unthreaded hole up to the head, with a nut then threaded on the other end; a heavy machine screw.]