identical twin

US /aɪˌden.tɪ.kəl ˈtwɪn/
UK /aɪˌden.tɪ.kəl ˈtwɪn/
"identical twin" picture
1.

bliźniak jednojajowy

either of two fetuses or children born at the same birth who have developed from the same ovum and are therefore always of the same sex and usually very similar in appearance

:
My cousins are identical twins; it's hard to tell them apart.
Moi kuzyni to bliźniaki jednojajowe; trudno ich rozróżnić.
She gave birth to a pair of healthy identical twins.
Urodziła parę zdrowych bliźniąt jednojajowych.