mix_in
1. [ verb ] cause (something) to be mixed with (something else) "At this stage of making the cake; blend in the nuts"
Synonyms: blend_in
Related terms: blend cut_in
2. [ verb ] add as an additional element or part
Synonyms: mix
Examples:

"mix water into the drink"

Related terms: add dash mix
Similar spelling:   mizen
  Mixon