Hyphens, En Dashes, Em Dashes
Q. Should “time travel” be hyphenated as a verb? CMOS 5.25 says it’s okay to use nouns as verbs, but there are no two-word examples. “Time travel” isn’t even in M-W!
A. According to our hyphenation guide at CMOS 7.89 (sec. 2, “phrases, verbal”), a verb phrase that doesn’t appear in the dictionary may be left open. Each of the examples in CMOS also appears in Merriam-Webster (where it is either closed, hyphenated, or open): babysit, handcraft, air-condition, fast-talk, strong-arm, sucker punch. Because “time travel” does not, it may be left open. (By the way, if you figure out how to travel through time, or time travel, and end up crossing paths with the Time Traveler from the classic novel by H. G. Wells, please say hello from us.)