This word – as “staggerment” – is featured in a very unusual paragraph:

[12.015]  To say that Bilbo’s breath was taken away is no description at all. There are no words left to express his staggerment, since Men changed the language that they learned of elves in the days when all the world was wonderful.

How gently we are reminded of the frame!  Here we see the hand of the Oxford professor entrusted with translating the journal.  We’ve seen him invent hyphenated words to get his job done, but “there are no words”!  And then the briefest of discourses on language history.  The very lightest touch.

• 04.046 and staggered along
• 09.001 and staggered on
• 12.015 There are no words left to express his staggerment,
• 12.077 Staggering!’