F2M stands for "Female to Male." It is a category in the transgender adult film industry, where the focus is on content featuring females transitioning into males. This can include pre-op, post-op, or non-op (meaning not undergoing surgery) trans men. The term F2M is used to distinguish this specific niche from other categories like M2F (male to female). It refers to adult content meant for an audience interested in transgender male experiences and transformations.