>_arcastar mondósaresse_

Very interesting! I cannot resist analyzing this right away:

_mondósaresse_ 'in Oxford'

In Letter no.342 Tolkien gives "the elvish word for 'bull'" as _mundo_
(apparently in Quenya), so that one can identify _mondo_ 'ox' here.
An element 'ford, crossing' would be then expected to follow and
indeed _-sar-_ can be related to THAR- 'across, beyond' (V:392), also
_thar-_ 'athwart, across' in the _Silmarillion_ glossary with _Tharbad_
< _thara-pata_ 'crossway'.

[Note also numerous Q. words in _sar-_ having to do with stones or
stoniness, as _sarne_ 'stony place' < SAR- (V:385, VT46:12). CFH]

The long _-ó-_ seems to suggest that one should isolate _#ósar(e)_
'ford', rather than just _#sar(e)_ with the prefix _ó-_ 'used in words
describing the meeting, junction, or union of two things or persons,
or of two groups thought of as units' (XI:367); and _-s-_ < _th_ would
naturally resist rhotacism here.

The ending _-sse_ is of course locative, while the vowel _-e-_ before
it may belong to the preceding word (#_ósare-sse_) or just link the
ending to it (#_ósar-e-sse_).

_arcastar_ 'Tolkien'

Tolkien's name is an anglicization of _Tollkiehn_ , German _tollkühn_
'foolhardy, reckless, desperately brave' (compare Letter no.165),
containing _toll_ 'insane, mad, wild' and _kühn_ 'brave'. A more or
less literal translation into English Tolkien himself also made, was
'Rashbold' (IX:151).

I would analyze the Quenya word as _*arca-star_.

The initial element _arca-_ looks similar to Q _arauka_ 'swift,
rushing' (PE12:34) from RAVA or RAWA (PE12:79) with many derivatives
for chase, running, hunting, fierceness; also _rauka_ = _arauka_ 'swift'.
But of course a diphthong cannot be syncopated, so that one has to
assume a different derivation from a changed or parallel root, e.g. <
_*araka_ < (A)RAK- (?); cf. Q _narka_ 'to rend' from NÁRAK- 'tear, rend
(tr. and intr.)' (V:374, VT45:37).

The latter element _-star_ seems to be related to STAR- 'stiff'
(V:388), with _st_ preserved medially. Although this stem yields words
for grass only — Q _sara_ 'stiff, dry grass, bent', N _thâr_ 'stiff
grass' and so on — there is a different root TÁRAG- 'tough, stiff'
producing Q _tarya_ 'tough, stiff' and N. _tarias_ 'stiffness, toughness,
difficulty', _tarlanc_'stiff-necked, obstinate' with reference to more
abstract meanings. Hence, _arcastar_ would be something like
*'rushing [and] stiff-necked'.

[I like your analysis, though I think _-star_ as 'stiff' (without any
reference to necks) is a fine rendering of the sense of 'hardy' in
'foolhardy', both as physically 'hard, tough' and as metaphorically
'unyielding, resolute'. CFH]

Roman Rausch