Definition of "unmasculine"

Characteristics labeled as unmasculine or as failure to conform to gender expectations include observable behaviors such as avoidance of rough-and-tumble play, typical boys' games, and athletic activities; no imagining of oneself as a sports figure; and no desire to grow up to be like one's father.

1998, Ritch Williams-Savin, …And Then I Became Gay: Young Men's Stories‎, Routledge

A fag is profoundly unmasculine, yet possesses the ability to penetrate and thus render any boy unmasculine.

2007, C. J. Pascoe, Dude, You’re a Fag: Masculinity and Sexuality in High School, University of California Press, page 157