While wussy is a term that is in common usage, in the pickup community it has the specific connotations of a man who is not successful with women because he is approval seeking and does not realize what it takes to attract a woman. The term was popularized by David Deangelo in his Double Your Dating materials.
Wussies display all the traits of a beta-male and go about trying to win the approval of women, instead of attracting them. Wussies supplicate to women, and easily, and even willingly, cave into shit tests and compliance tests, believing that doing so will get women to like them. In fact, all they do is display low status behaviors and repel women away from them.
Wussy behavior is not limited to AFCs. Even experienced PUAs can occasionally fall into wussy behavior patterns when they are stricken by the beauty or attractiveness of a particular woman. The best way to prevent this from happening is to always strive to remain outcome independent, not giving special treatment to women just because of their beauty.
Source: David Deangelo