It stands for exchangeable variable rate note; a variable rate note (floating rate note) that pays a floating coupon after a predetermined date; before this date the note pays a fixed coupon. The initial short term over which the coupon is fixed is known as the teaser period. It is after the passage of this period that the interest rate changes from fixed to floating (such as the 90-day bill rate, the prime rate, etc.)
Usually, exchangeable variable rate notes come with the option for the issuer to exchange them to fixed coupon notes.
