Why Gulliver exactly? It’s now such a familiar name that we no longer ask. But it seems to have been carefully chosen. A ‘gull’ is slang for a fool or dupe, a trustful person, an ‘innocent abroad’; and to ‘gull’ someone is to trick or fleece them. The term was common in Swift’s day; the OED gives the earliest citation as 1594, from the work of Thomas Nashe: 'Liues there anie such slowe yce-braind beefe-witted gull.’ From 1748, closer to the publication-date of Gulliver’s Travels (in 1726), we have a citation in Smollett: ‘If I had been such a gull...I would without more ado tuck myself up.’ By the late nineteenth century the term was dying out. The OED’s last citation is from 1885 in the work of Robert Louis Stevenson: ‘He perceived by what...unmanly fear of ridicule he had been brought down to be the gull of this intriguer.’ Gulliver is not a fool, nor a dupe, but he is certainly trusting. And he is met everywhere with freaks and impossibilities which he is expected to take seriously - as are we, the readers. Gulliver may not be a fool but there is no shortage of fools in Gulliver.
The syllable ‘ver’ seems also to have been significant. It suggests truth (as in ‘veracity’), a point echoed in Swift’s foreword to Gulliver’s Travels, written under the pseudonym of Richard Sympson and itself an exercise in pseudo-deception: ‘There is an air of truth apparent through the whole; and indeed the author was so distinguished for his veracity, that it became a sort of proverb among his neighbours at Redriff, when any one affirmed a thing, to say, “it was as true as if Mr. Gulliver had spoken it.”’ Gulliver, then, as a name, opposes deception with truth. What better nomenclature for the hero of a work of satire, in which the satirist peddles monsters and exaggerations in the service of righteous and truth-telling anger?
On a final note of pedantry: Gulliver’s Travels is not the title of the book at all. It was originally Travels into Several Remote Nations of the World, in Four Parts. By Lemuel Gulliver, First a Surgeon, and then a Captain of Several Ships.
Seronsy, Cecil C: ‘Some Proper Names in Gulliver’s Travels’, Notes and Queries 202 (1957), 471