Hart/hɑːrt/ Definition 1 of 3Pro Tip 1/3Older Deer Use 'hart' for male deer over five years old, not for young or female deer. The old hart stood majestically amongst the trees. Pro Tip 2/3Historical Usage 'Hart' is an archaic term, more common in historical or literary texts. Knights often hunted the hart in medieval times. Pro Tip 3/3Nature Descriptions Employ 'hart' to enhance descriptions of natural settings in creative writing. A solitary hart was silhouetted against the dawn sky.