The Dhammapada 9 & 10 

Who is not rid of defilement and will wear a yellow robe,

devoid of restraint and truth, 

he does not deserve a yellow robe.

This verse as well as the following one (DhP 10) talks about who is and who is not worthy to wear a monk's robe. One, who did not get rid of defilement (anikkasāvo), who is full of these impurities, who does notknow self-control and restraint (dama) and who is far away (apeto) from truth (sacca), does not deserve to wear a yellow robe. Such a person can not call himself a monk, even if he should be dressed in the monk's robe. 

A defilement (kasāva) is  usually understood to be the , three roots of evil: lobha (greed), dosa (hatred) and moha (delusion).

And who would get rid of defilement, well settled in virtues, 

Endowed with restraint and truth, he deserves a yellow robe.

In contrast to DhP 9, the person, who deserves to wear a monk's robe is described here. Who "threw up", or got completely rid of, defilement (vantakasāvo), who is well settled and well established in his virtues (sīlesu susamāhito) and who is endowed (upeto) with restraint (dama) and knows the truth (sacca), such a person deserves to wear a yellow monk's robe. Such a person can truly be called a monk.