Today's Rutti v. Lojack Corp. has the following passage:

Mike Rutti sought to bring a class action on behalf of all technicians employed by Lojack, Inc. (“Lojack”) to install alarms in customers’ cars. He sought compensation for the time they spent commuting to worksites in Lojack’s vehicles and for time spent on preliminary and postliminary[1] activities performed at their homes.... [W]e vacate the district court’s grant of summary judgment on Rutti’s postliminary activity of required daily portable data transmissions ....

[Footnote 1:] Although not in the dictionary, this word is used in the critical statute, 29 U.S.C. § 254(a)(2). The statute provides that an employer need not pay for:

activities which are preliminary to or postliminary to said principal activity or activities, which occur either prior to the time on any particular workday at which such employee commences, or subsequent to the time on any particular workday at which he ceases, such principal activity or activities.

There is some inherent ambiguity in this definition. On the one hand, these terms refer to the timing of the activity as either before or after the employee’s primary job functions. On the other hand, the terms appear to be used to distinguish off-the-clock activities for which an employee is not entitled to compensation from “principal activities” for which an employee is entitled to compensation. In this opinion, the terms are used primarily to refer to the timing of the activities in issue.

I often like to note unusual legal words, so that's one reason for the post. But another reason is to remark on the "not in the dictionary" locution. Of course, there is no "the dictionary"; and while the word doesn't seem to be in any of the major online free dictionaries, it is in the Oxford English Dictionary — surely a dictionary, whether or not you see it as the dictionary.

The first definition in the dictionary turns out to be legalese, though quite different from the meaning in the statute. The word "postliminy" is listed in the OED as "Roman Law. The right of a banished person or captive to resume civic privileges and former rights on return from exile (hist. in later use). Hence Internat. Law: the restoration to their former status of persons and things taken in war." "Postliminary" is then defined as "Relating to or involving the right of postliminy."

But the second definition is simply "Coming after, subsequent. Opposed to preliminary." The earliest source is 1826, in a novel by Sir Walter Scott (a pretty good source as sources go), though a Google Books search revealed an 1811 source as well. And of course the existence of the word is to be expected, given the way English words are often formed.

Nor is the ambiguity identified by the court some artifact of the suspect, supposedly not-in-the-dictionary nature of the word "postliminary"; rather, the ambiguity is in the statutory definition, and applies to "preliminary" as well.

Now I wouldn't urge people to use the word "postliminary," unless they're dealing, as did this case, with a particular statute that uses the word. The word strikes me as unidiomatic (that it's not in the standard one-volume desk dictionaries is indeed a sign of that), and as clunky and distracting, even when the meaning is obvious. But it is in at least one pretty important dictionary, and isn't entirely a nonce word on Congress's part.

Thanks to Gabriel Malor for the pointer.