1. To gradually become the same as or a part of something else: Damien was blending three colors of paint into one.
2. To mix things thoroughly and usually with good results: Salina often blended fresh fruit and yogurt together for an afternoon snack.
3. To exist together as a combination: Two or more words are blended together to create the word “portmanteau”.

One example of a portmanteau is when "slang and language" are blended into "slanguage".