Similar words:

gýliboð
gýlifengur
gýll
gýlserkur

They're all listed in the Orðabók Háskólans Ritmálsskrá, but it only
has examples for 'gýligjöf'. The source of 'gýll' is Annálar 1400-1800
(Annals), so it may well be the word for sundogs/parhelion that's in
CV. I don't know about the rest...

>
> > gýligjafar
> > golden? gifts
>
>
> I don't know.
>
>
> The Orðabók Háskólans Ritmálsskrá has some examples of the word in
> later Icelandic [
>

http://lexis.hi.is/cgi-bin/ritmal/leitord.cgi?adg=daemi&n=172061&s=204055&l=g%FDligj%F6f

> ]. Some of them, where there's a scathing connotation, call to mind
> the English word "blandishments" (e.g. Gýligjafir munu ekki blekkja
> hann.), although this is presumably too abstract and negative a
> translation for all of these examples (e.g. the first).
>
> It appears here in a list of semantically related words [
>

http://www2.hu-berlin.de/bragi/b8/tho/b8tho_05_gestrisni_og_gjafir_kh.htm

> ], gifts and precious objects.
>
> But I can't find it in Fritzner or CV or Zoega. CV has a word 'gýll'
> "mock sun, parhelion", 'gýla-ferð' being the incidence of such a
> phenomenon [
> http://lexicon.ff.cuni.cz/png/oi_cleasbyvigfusson/b0222.png ], but I
> don't see how this would relate to gifts. In 'gull' "gold" (neuter),
> both 'l's belong to the root. So 'gýli-' would appear not to be
> etymologically related to 'gull' (the same goes for 'gylla' "to gild",
> including the expression 'gylla hóli' "to flatter", as this verb is
> derived from 'gull').
>
> Müller just has 'ok gaf Bergþóra þeim gjafir' [
> http://books.google.co.uk/books?id=Z1QEAAAAQAAJ&pg=PA138 ], although
> 'gýligjafar' does appear at the corresponding point in Konráð Gíslason
> and Eiríkur Jónsson's edition [
>

http://dp.rastko.net/projects/projectID438a3f4017f9f/projectID438a3f4017f9f_TEI.txt

> ].
>
> ('gjafir' and 'gjafar' are just alternate forms of the plural.)
>