1Cousin — the child of one's aunt or uncle. In speech, いとこ covers cousins of any gender and is normally written in kana. The kanji spelling encodes gender and relative age: 従兄弟 for a male cousin (従兄 if older, 従弟 if younger), 従姉妹 for a female one. Read with its on'yomi as じゅうけいてい it means specifically a male cousin, but that is stiff, document-style Japanese and virtually never heard in conversation.
私にはいとこが五人いる。
I have five cousins.
夏休みは、いつも田舎のいとこの家に泊まりに行っていた。
Every summer vacation, I used to go stay at my cousin's house in the countryside.
いとこの結婚式に招待されて、久しぶりに親戚が集まった。
I was invited to my cousin's wedding, and the relatives all got together for the first time in ages.
彼とは年が離れているけれど、実はいとこ同士なんです。
There's a big age gap between us, but we're actually cousins.
母方のいとこは、みんな関西に住んでいる。
My cousins on my mother's side all live in the Kansai area.