Definition of Repeated nightmares:

Repeated nightmares are bad dreams that recur frequently and involve the same theme.

Nightmares usually begin before the age of 10 and are considered a normal part of childhood, unless they significantly interfere with sleep, physical development, or psychosocial development. They tend to be more common in girls than in boys. Nightmares may continue into adulthood.

Nigthmares are different from night terrors.