D. Hindley uses the word cruelly, almost as a racist pejorative, to alienate Heathcliff and make him feel his outsider status.
The term "gipsy" carries connotations of otherness and prejudice, indicating not only Hindley's disdain for Heathcliff but also reflecting social attitudes of the time that marginalized and stigmatized those perceived as different. This adds to the conflict and tension in their relationship, emphasizing Heathcliff's position as an outsider.