When Oxford Dictionaries included the word 'vape' into their international lexicon, they defined it as either a verb or a noun:
vape, verb: Inhale and exhale the vapour produced by an electronic cigarette or similar device
vape, noun: An electronic cigarette or similar device; an act of inhaling and exhaling the vapour produced by an electronic cigarette or similar device
But, the popular English dictionary isn't the one that coined the word to describe a new type of nicotine delivery system. It was a doctor in the 1980s named Norman L. Jacobson who introduced the concept of vaping to the American College of Chest Physicians in Houston, TX. His paper was titled "Non-Combustible Cigarette: Alternative Method of Nicotine Delivery."
He explained to his colleagues how the non-combustible cigarette or NCC worked. He also said:
To our knowledge, a method of inhaling pure nicotine vapour has not been reported previously. To simplify description, we will hereafter refer to nicotine vapour inhalation through an NCC as vaping and people who inhale nicotine vapour as vapers.
The Ashtray Blog provided supporting evidence of this through scanned newspaper clippings.
Dr Jacobson, who ran a trial on the device, described the use of the device as vaping, and called the people who used it vapers.
And a trial came up with similar results to more modern studies; vapers showed reduced cotinine levels, carbon monoxide levels were at the same as those of non-smokers, and vaping appeared to be more effective for experienced vapers than naive vapers.
Dr Jacobson suggested that the reason experienced vapers found the devices more effective is because they had to learn, like smokers, how to self-titrate – that is, they had learned to [use] the devices so they took enough nicotine to satisfy their needs.
You can also read Ashtray Blog's interview with Doctor Jacobson here.