Also known as the extreme left, ultra left or radical left, this term is often used pejoratively (and sometimes simply descriptively) to refer to politics further on the left of the left-right spectrum than the mainstream political left. This often includes anarchists and communists - and a higher degree of leftism generally. Often anti-property, anti-capitalist, anti-fascist, anti-liberal, and anti-conservative.
More substantively, this term is used to refer to people who declare a total opposition to capitalism or property, such as anarchists and some Marxists. The term is also used to refer to those who offer a highly critical analysis of capitalism, e.g. of capitalism as inevitably leading to great inequality, lack of social mobility for most, destruction of the environment, and the domination of labor and of small businesses by enormous oligopoly firms with great political power.
For conservatives, the term ‘far left’ is used pejoratively to refer to anyone thought to be in favor of a government "takeover" of "everything.” Popularly associated with Marxism, these ideas typically evoke automatic condemnation and fear from many Americans on the right - ‘hasn’t this already been tried in the USSR?’ To those on the left, however, this reflects profound misunderstanding not only of Marxism but leftist thought generally - as well as a silencing and discrediting of liberal and leftist voices in society as merely “extreme.”