I'm up here in Maine. Dad was a carpenter/contractor/developer as was his father ... I was never formally trained but worked for dad during HS and college vacations. He always called them casement windows ... and if 2 were placed together opposing each other as a set, he called them double casement windows. In most of the homes I was involved with, we installed double hung windows, very few casements. I have no idea what the preferred name is in 2024, much has changed in nearly 50 years. We didn't have cordless tools, nail guns, laser levels, etc.