Tithonus

Tithonus, a handsome youth, was snatched from the palace of his father, king Laomedon, by Eros, goddess of the dawn. His mother was either Strymo, Placia or Leucippe. Some writers say Eros turned him into a cricket, and that his name comes from the Greek word for this insect, tettix.

Again, Zeus made Tithonus immortal (but not ageless) so that this extension of his life may be reflected in his name if it contains the element teino, 'to stretch'. A more likely source would be tithemi, 'to put', 'set', 'order' (as for Themis, Thetis and Theseus), referring to one who was 'ordered' by the goddess of the dawn, who reigns daily in a preordained manner.

One of the more obscure explanations is offered by the Classica Manual, where the name is 'said by some to be derived from two words implying "the mount of the sun" ... Tithonus being nothing more than a tower, sacred to the sun'. Compare this same tome's explanation for Triton.