You can find six meanings stated in OED's entry with the noun masthead, two of which might be labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence. This instance is from Wikipedia and could be reused under a CC BY-SA license. Inside a cutter rig, the jib https://yfovbgo.blogkoo.com/a-secret-weapon-for-masthead-45930615