1599, William Shakespeare, , First Folio edition, Act V, Scene 1:A Contract of eternall bond of loue,Confirm'd by mutuall ioynder of your hands,Atteſted by the holy cloſe of lippes,
(linguistics) Of words or languages, proven to have existed by records.
2010, Alexander Humez, Nicholas Humez, Rob Flynn, Short Cuts: A Guide to Oaths, Ring Tones, Ransom Notes, Famous Last Words, and Other Forms of Minimalist CommunicationA term should be included if it's likely that someone would run accross it and want to know what it means. This in turn leads to the somewhat more formal guideline of including a term if it is attested and idiomatic.
The word slæpwerig (sleep-weary) is attested in the Exeter Book in the form slæpwerigne.
