When I say "electric dulcimer," I'm referring to a dulcimer that uses magnetic pickups. You'll also find lots of essentially acoustic dulcimers on the market that have various kinds of piezo pickup systems. Personally, I find magnetic pickups to be much more versatile and expressive.
I play three electric dulcimers: 1) an electric mountain dulcimer I built from an old cypress ironing board, 2) an electric mountain dulcimer that I heavily rebuilt from a Tom Yocky electric model, and 3) an electric chromatic dulcimer that I built from a plank of aspen.
Folks on dulcimer discussion groups sometimes opine that "electric dulcimers" are essentially anti-dulcimer, contending that "you might as well play electric guitar!" (this very phrase seems to be something of a recurring theme). As someone who plays both guitars and dulcimers, acoustic and electric each, I do not find this negativity to be warranted.