This term for a non-rigid airship is of uncertain origin. We do know that it was coined during the First World War, but who coined it and why the rather enigmatic term blimp was chosen may never be known. Making matters worse, the various origin stories are often conflated in various sources, making sorting out the truth difficult.
First, the earliest known use of the term dates to February 1916, from Rosher’s In R.N.A.S.:
Visited the Blimps...this afternoon at Capel.
The most popular explanation seems to be that blimp is from a classification system for airships, Class-A Rigid and Class-B Limp. The problem with this explanation is that this alleged classification system is found nowhere except in explanations of the origin of blimp and the word limp was not applied to lighter-than-air craft during WWI.
More likely, the name is a humorous appellation of the sound made when one strikes the airship’s gas bag. There is even a very specific origin story associated with this. Supposedly, in December 1915 Lieutenant A.D. Cunningham, the commander of the Royal Naval Air Service station at Capel, Surrey did just this and muttered “blimp” in imitation of the sound. The officers and men present were amused and the term caught on as the name for the airships.
The Illustrated London News printed the onomatopoeic explanation in July of 1918, although it credits aviator Horace Shortt, not Cunningham, with the coinage:
Nobody in the R.N.A.S. ever called them anything but “Blimps,” an onomatopoeic name invented by that genius for apposite nomenclature, the late Horace Shortt.
Whether it was Cunningham or Shortt is a question.
Complicating matters further is that one of the citations in the OED gives yet another explanation. This normally could be dismissed, except for its source. In 1926, J.R.R. Tolkien offered this speculation (remember he was a distinguished Oxford linguist and staff member of the OED who only wrote fantasy stories in his spare time):
It is perhaps more in accordance with their looks, history, and the way in which words are built out of the suggestions of others in the mind, if we guess that blimp was the progeny of blister + lump, and that the vowel i not u was chosen because of its diminutive significance—typical of war-humour.
Despite the source, this explanation is certainly wrong.
Copyright 1997-2015, by David Wilton