Definition of "stepsibling" [stepsibling]

• A stepbrother or a stepsister. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Among other 2009 findings for kids under 18:•69% lived with two parents.•4% lived with both a mother and father not married to each other.•59% who don't live with a parent lived with a grandparent.•7% lived with an unmarried parent who was cohabiting.•16% lived with a stepparent, stepsibling or half sibling."
• "Many therapists also shun the term, which seems to confer second-class status on a stepparent or stepsibling."
• "About 12 percent had at least one half-sibling, and 2 percent had a stepsibling."