According to the Collins dictionary, to slam someone or something means to criticize them very severely. It also means to move against a hard surface with force and usually a loud noise.
However, in literature, slam is considering a form of poetry known as slam poetry that combines the elements of performance, writing, competition, and audience participation. It is performed at events called poetry slams, or simply slams.
The name slam came from how the audience has the power to praise or, sometimes, destroy a poem and from the high-energy performance style of the poets.
This edition of the program highlights slam as an act of criticizing immoral acts