The word "uncircumcised" refers to a state where a male has not undergone circumcision, a surgical procedure that removes the foreskin from the penis. In this context, being uncircumcised means that the foreskin is still intact and covers the glans (the tip of the penis).
The word "uncircumcised" is derived from the prefix "un-" meaning "not," and "circumcised," which comes from the Latin "circumcidere," where "circum-" means "around" and "caedere" means "to cut." Therefore, "uncircumcised" literally means "not cut around."