Q. I’m editing a list of security recommendations. Would you put a hyphen in “password-protect” when used as a verb?
A. According to the hyphenation guide at CMOS 7.96 (sec. 2, under “phrases, verbal”), compound verbs like that one are left open unless entered in Merriam-Webster with a hyphen. There’s no entry there for that verb, hyphenated or otherwise, so we’d write password protect.
If you strongly prefer the hyphen, you could cite the OED, which does include an entry for the term, where it’s hyphenated (password-protect). The OED mostly reflects British usage, but many similar verbs are listed in either Merriam-Webster or the OED with a hyphen (e.g., double-click, fact-check, hot-wire, fast-forward). And though the term password-protect isn’t listed in either Microsoft’s or Apple’s style guide, the similar verb write-protect is listed in Microsoft’s guide (and in the OED) and copy-protect is entered in Apple’s guide (all as of February 3, 2026).
In sum, Chicago style would call for password protect (no hyphen), but the hyphen is nonetheless a reasonable choice recorded in at least one major English-language dictionary and reflected in similar terms.