Inglorion

The surname given to himself by the Elf Gildor when he met Frodo and his companions in Woody End in the Shire. Inglorion is a patronymic, and means 'son of Inglor'.

This interpretation means that Gildor was potentially a very important Elf indeed, because at the time these words were written, Inglor was the name of the Elf-lord called 'Finrod' in The Silmarillion, and the name Finrod belonged to his father (known in The Silmarillion as 'Finarfin'). This suggests that Gildor was of very noble descent, and was in fact the son of the founder of Nargothrond.

It's hard to tell whether or not this was Tolkien's intention when he chose the names. In The Silmarillion, it's stated categorically that Finrod (equivalent to Inglor in this context) had no wife or children, which seems to contradict Gildor's claim. This may simply be a case of Tolkien using an existing name without intending any particular significance (as he did, for example, with 'Glorfindel'), but it's possible to speculate that the name Inglorion carries much more meaning than might appear on the surface.