Verb: To lie, making your friend look like a huge creeper to the boy she likes, while having done none of the things you said she did. In fact, in some cases, YOU did the things that caused your friend to look like a creep.
Can be thought of as a bitchy move. Karma well come back to haunt anyone who had Caldered.
"Hey Calder, My friend was taking pictures of you while you were snowboarding... Look!"