Contiguous (कन्टिग्यूअस) adjective
Contiguous means touching or sharing a common border, or close together without any gap (सटा हुआ / जुड़ा हुआ)
India and Nepal are contiguous countries.
The hotel has three contiguous buildings.
Contagious (कन्टेजस) adjective
Contagious means spreading by contact, especially a disease or emotion that can easily pass from one person to another (संक्रामक / फैलने वाला (रोग या भावना))
COVID-19 is a contagious disease.
Her laughter was so contagious that everyone started laughing.