Meaning and usage of Grimnir?
Interest in this epithet of Odin's was renewed when it was casually tossed out in a recent episode of American Gods. *
My question has three parts:
What is the meaning of Grimnir? I found this Old Norse lexical entry for grimmr but welcome more detail.
Is this epithet restricted entirely to the Grímnismál or is it common across the canon?
Is it correct that the use of "grim" in names is a reference to Odin. Thorgrim, Hallgrim, Skallagrim, etc.
* I mention the work that prompted the question because I consider Gaiman an exemplar of modern adaptation of mythological material. It is worth noting that the de facto name for Odin in American Gods is "Mr. Wednesday".
Grím seems to be a variant of "Grímnir", which means "masked person". A very apt name for Odin. The closest English equivalent is "grimace", while "grim" (similar meaning in old Norse and modern English) seems to be distantly related, and only appears as a byname of Odin, "Asagrim", in a medieval Swedish ballad. (Note the difference between "Grím" and "Grim").
Grímnir and Grím both appear in Grímnismál, they also appear in a portion of Snorri's Edda dealing with the names of Odin. Grímnir also appears in Scaldic poetry as a name for Odin. Wikipedia has a useful list of names of Odin which also gives which sources they appear in.
The other names where "Grím" is a part are likely just names (in particular, "Thorgrim" already has the name of one God as a part, and would not seem to need another one). Note that it's actually "Skalla-Grím", 'bald Grím'.
For etymology, I consulted Nordiskt runnamnslexikon, a list of names appearing on runestones. It gives "GrímR" -"someone who wears a mask".
I also checked Thorgrim and Hallgrim in the database of Nordiska museet. I only found "Torgrim", but it did not indicate any connection with Odin. "Hall" means "stone".
An old Norse version of Gylfaginning can be found here.
Thanks for that lexical link! (The Old Norse lexicon on Perseus, alas, appears to be quite lacking. Haven't been able to search with the accent, and even directly linking "Grímr" from Gríms saga yields an empty page.) The mask definition is elucidating, and provides a better understanding on why Gaiman used it where he did.