Where did the term stepparent come from
The American College Dictionary (1970) says the prefix "step" comes from the old English steop-, which meant "related by marriage rather than blood." A related root is the Icelandic stjup-, denoting bereaved or orphaned. Microsoft's Bookshelf describes a current secondary meaning of stepchild as "Something that does not receive appropriate care, respect, or attention."
Source The word 'steop' is an old Teutonic word denoting bereavement, so a 'steopbairn' was a child who had lost a parent and gained a stepparent. As has been portrayed in many old folk tales the very gaining of a stepparent was often associated with loss and hardship.
Overall, "step" terms are widely used to denote derogatory meanings. Stepfamilies have been considered even by well-meaning people as less valid than nuclear families, or perhaps to be pitied.
(The word "step" comes from the Old English word "steop", which meant "bereaved"; a stepchild then was understood to be an orphan. Perhaps some of the current bias comes from that historical perspective.)
Because of this bias, some stepfamilies try to masquerade as nuclear families. However, this pretense denies the realities of the new family structure and can add pressure to the individual members. Rather than accepting the sense of stepfamily life as being somehow "second best", stepfamily members can actually feel proud of their status because, in fact, their family has come together out of choice and not by chance.
Stepfamily adults have chosen to begin this new life, willingly taking on the children, choosing them as special and wanting to shape a new, inclusive group. Source The prefix "step" conjures up images of Cinderella's wicked stepmother or Hansel and Gretel being sent out into the forest. Nevertheless, it is the term of choice for several reasons.
First, the word "step" is derived from an Old English word - "steop" - which means "orphaned or bereaved." For hundreds of years, it was following the death of a spouse that adults with children usually remarried. Thus, most children in such families were, in fact, "steop-children." (You may recall that in the story of Cinderella, her own mother had died).
Another reason to use the term "step" is that alternative labels have problems of their own. The idea of a "blended" family suggests that people can be integrated and woven together much as manufacturers make blended fabrics.
In time, this is the best outcome of any new family, but the beginnings rarely appear smooth or artfully designed. Worse than "blended" is the notion of a "reconstituted" family. This implies that new families, like rehydrated fruit, can recreate something which existed before. Nothing could be further from the truth! There were other families before, but the new family is not a refurbished version of the previous groups.
Stepfamily Association of America
The Australian Bureau of Statistics states a blended family is formed when the parents in a step family then have a child together.