"4. Etc. The use of "etc." as a part of our evaluating processes leads to awareness of the indefinitely many factors in a process which can never be fully known or perceived, facilitates flexibility, and gives a greater degree of conditionality in our semantic reactions. This device trains us away from dogmatism, absolutism, etc. We are reminded of the second premise (the map does not cover all the territory) and indirectly of the first premise (the map is not the territory)."
— Alfred Korzybski, The Role of Language in the Perceptual Processes.
This extensional tool also points out the second premise (not all), helps us get rid of "either/or" formulations, etc.
Each time you use this word, try to consider at least one additional item of your enumeration, so that is not just a "way to speak".
Korzybski made such a heavy use of this word in Science and Sanity
that it was necessary to use a simplified notation:
The abreviation Stands for . , etc., , . ,etc. , ; etc.; . ? etc.? . : etc.: . ! etc.!