July’s full moon is called "the Buck Moon” because in July, velvet antler growth, called antlerogenesis, makes an older buck’s rack often very noticeable and actually at its peak growth rate.

The Old Farmer's Almanac, which began publishing full moon names in the 1930s, says some Native American tribes called July's full moon the "buck moon" because it occurs in early summer, when male deer (bucks) typically begin growing new antlers covered in velvety fur.