What is the meaning of -ism?

Used to form nouns of action, process, or result based on the accompanying verb ending in -ise or -ize.

Used to form the name of a school of thought, system, or theory based on the name of its subject or object or alternatively on the name of its founder

Used to form names of a tendency of action, behaviour, condition, opinion, or state belonging to a class or group of persons, or the result of a doctrine, ideology, or principle or lack thereof.

Used to form countable nouns indicating a peculiarity or characteristic of language

Used to form names of ideologies expressing belief in the superiority of a certain class within the concept expressed by the root word, or a pattern of behavior or a social norm that benefits members of the group indicated by the root word.

Used to form names of conditions (syndromes, diseases, disorders, defects, addictions) and therapeutical methods or doctrines.

Alternative form of ism (ideology or form of discrimination ending in -ism)

-ism

-ism

Source: wiktionary.org