"Vaping" is apparently the practice of smoking one of 'em newfangled e-cigarettes. Where does the word come from and when was it first used?
The verb to vape is new to me but refers to the act of using an e-cigarette. Given the relative novelty of e-cigarettes it's unsurprisingly a new term. It's used to differentiate from smoking a traditional cigarette, as e-cigs don't give off smoke but instead give off a vapour.
Users may wish to emphasise this point, and some claim it's less (or not at all) harmful for them and those around them, although this isn't fully understood yet. E-cigarettes are becoming more popular, and regulators haven't fully decided how to deal with them, so the term may grow in popularity, although it may sound too close to rape for others.
The earliest definition of vape on Urban Dictionary is from Mar 31, 2004, a noun and verb back-formed from vaporizer, and is currently the second highest voted definition:
The highest voted is the e-cigarette meaning, from Jan 13, 2009, back-formed from vapor, as opposed to the verb smoke from traditional cigarettes:
Usenet and forums
Vape as in a vaporizer can be found at least as early as 1998, probably much earlier. Unsurprisingly, it's much more recent when referring to relatively new e-cigarettes. Here's a April 24, 2008 post on e-cigarette-forum.com:
The earliest I found on this forum is from the forum founder pondering in an early post on December 18, 2007:
A few months later, someone else was happy to use vape in a March 2, 2008 post:
And the same user later that day:
It's now been accepted by the online e-cig community. On the top of every page is a current appeal to vaping Europeans and Americans (along with a safety recall for a device called SLB Vapros V1):
The Urban Dictionary has an entry for this sense, but there are also entries for its use in the smoking of marijuana through a vaporizer, which seems to be its provenance. The Urban Dictionary doesn’t give dates of first use, but the source word vapour is ultimately from the Latin word for steam.