'Stepbrother' definitions:
Definition of 'stepbrother'
From: WordNet
noun
A brother who has only one parent in common with you [syn: stepbrother, half-brother, half brother]
Definition of 'Stepbrother'
From: GCIDE
- Stepbrother \Step"broth`er\, n. A brother by the marriage of one's father with the mother of another, or of one's mother with the father of another. [1913 Webster]