A beautiful Trojan beloved by Aurora. He begged the goddess to grant him immortality, which request the goddess granted; but as he had forgotten to ask for youth and vigour he soon grew old, infirm, and ugly. When life became insupportable he prayed Aurora to remove him from the world; this, however, she could not do, but she changed him into a grasshopper. Synonym for “an old man.”
An idle scene Tithonus acted When to a grasshopper contracted.
Thinner than Tithonus was Before he faded into air.
Tales of Miletus, ii.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894