informalism

A word, phrase, behaviour, etc. that is informal.

At other times, in complete contrast, as noted elsewhere (Section 7.3), there is frequent recourse to slang and informalisms. Speech style in this sense is closely connected to footing.

The reason we don't, he said, is because our educational system has swung too far in the direction of formal methods and has neglected such informalisms as common sense and natural language communication.

An art movement based on abstract and gestural tendencies rather than definite form.