- a distinctive doctrine, theory, system, or practice: This is the age of isms.
- a suffix appearing in loanwords from Greek, where it was used to form action nouns from verbs (baptism); on this model, used as a productive suffix in the formation of nouns denoting action or practice, state or condition, principles, doctrines, a usage or characteristic, devotion or adherence, etc. (criticism; barbarism; Darwinism; despotism; plagiarism; realism; witticism; intellectualism).
- an unspecified doctrine, system, or practice
- interstellar medium
- indicating an action, process, or result
- indicating a state or condition
- indicating a doctrine, system, or body of principles and practices
- indicating behaviour or a characteristic quality
- indicating a characteristic usage, esp of a language
- indicating prejudice on the basis specified
