The act of turning someone or yourself into a sissy, often via sissy hypno, a
chastity cage, and wearing feminine clothing.
Being a sissy isn't the same as being a trans woman, as sissification is done as a fetish, and isn't the same as
transitioning, though trans sissies do exist.
Sissification is mostly done in femdom
relationships and is often combined with other things like cuckolding