1) Like boys who will be boys 2) Opposite of T in LGBT 
Cisgender and cissexual (often abbreviated to simply cis) describe related types of gender identity where individuals` experiences of their own gender match the sex they were assigned at birth. Sociologists Kristen Schilt and Laurel Westbrook define cisgender as a label for `individuals who have a match between the gender they were assigned at b.....
a person who identifies with the gender indicated by their externally observable features. This is usually a sign of a healthy mind.
Cisgender means a person whose gender identity matches the sex they were assigned at birth. The abbreviation for Cisgeneder is CIS.
Individuals whose gender identity and expression line up with their birth-assigned sex.
individuals whose gender identity and expression line up with their birth-assigned sex.
Having a gender that matches one’s sex assigned at birth, their bodies, and their personal identity. Often referred to as cis-male or cis-female; this term is the antonym to transgender.