We don't have synonyms for mummock yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are hummock, mammock and bummock.
(v) :
Alternative form of mommick (“(dialectal:) to harass, bother”). [(dialectal, transitive, including Ocracoke Island North Carolina) To harass or bother (someone or something).]
(v) :
Alternative form of mommick (“(dialectal:) to harass, bother”). [(dialectal, transitive, including Ocracoke Island North Carolina) To harass or bother (someone or something).]