What it means to be circumcise?

Answer 1

If a male is circumcised then he has had a surgical procedure during which part of the skin of the penis, called the foreskin, is cut off. This leaves the head of the penis exposed and uncovered.
To be circumcised is to have circumcision performed. This is the removal of the foreskin, the skin and tissue that covers the head (glans) of a penis.

Circumcision is a tradition with Jewish families, in which the foreskin of the penis is cut off (along with a small section of the frenulum), when the boy is still a baby.