It describes how we do things differently, for example (6)
I believe the answer is:
adverb
This might be a double definition.
'it describes how we do things differently' is the first definition.
The definition suggests a singular noun which matches the answer.
'example' is the second definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'for' acts as a link.
Can you help me to learn more?
(Other definitions for adverb that I've seen before include "Word that modifies something other than a noun" , "Verb modifier" , "Word that modifies another" , "Word modifying an action word" , "Word to qualify an action" .)