For a cousin on your father's side:
* 堂兄 (táng xióng) - Male cousin
* 堂姐 (táng jiě) - Female cousin
For a cousin on your mother's side:
* 表兄 (biǎo xióng) - Male cousin
* 表姐 (biǎo jiě) - Female cousin
You can also use these more general terms:
* 堂兄弟姐妹 (táng xiōng dì jiě mèi) - Cousins (male and female) on your father's side
* 表兄弟姐妹 (biǎo xiōng dì jiě mèi) - Cousins (male and female) on your mother's side
* 兄弟姐妹 (xiōng dì jiě mèi) - Cousins (male and female) in general
Note:
* The terms for cousins on your father's side (堂) and your mother's side (表) are distinguished by different characters.
* The terms for male (兄) and female (姐) cousins are different as well.
Example:
* 我的堂姐住在美国。 (Wǒ de táng jiě zhù zài Měiguó.) - My female cousin on my father's side lives in America.
* 我和我的表弟关系很好。 (Wǒ hé wǒ de biǎo dì guānxi hěn hǎo.) - I have a good relationship with my male cousin on my mother's side.