noun. 1) A naughty name for an eco-minded person. 2) A nasty name for a resident of Earth, much like Earthie, Earthican, Earthwad, and Earthbutt.
Real citation: “Gosh, I put DM's 'community service' work right up there with ah...Plastic Duck's Unconscionable Rehabilitation. You know why? Well, no. 1, whenever some anti-globalist earthtard shines on with the enviro speak I sigh...and note that their dorm room alone consumes enough energy to power a small third-world village.”
(July 12, 2007, Second Thoughts, http://secondthoughts.typepad.com/second_thoughts/2007/07/tree-politics.html)
Made-up citation: “’Bow down, Earthtards!’ said the Martian warlord Xhulatula, as his faithful pack of peebots claimed the White House for the glorious red planet.”