'Stepsister' definitions:
Definition of 'stepsister'
From: WordNet
noun
A sister who has only one parent in common with you [syn: half sister, half-sister, stepsister]
Definition of 'Stepsister'
From: GCIDE
- Stepsister \Step"sis`ter\, n. A daughter of one's stepfather or stepmother by a former marriage. [1913 Webster]