1567, "showing despicable cowardice," originally "dull," from M.E. dastard (c.1440), from *dast "dazed," pp. of dasen "to daze" + -ard deprecatory suffix. The earliest sense of dastard was "one who is lazy or dull;" sense of "one who shrinks from danger" is 1470s.
[das-terd-lee] 
tərd