mush (something) up
To mash or crush something into a thick, soft pulp. Make sure you mush up that banana before you give it to Katie—she's still having trouble chewing solid food.
To squash or mash something into a soft, pulpy consistency. A noun or pronoun can be used between "mush" and "up." You can just mush up a banana for the baby at lunchtime. I had to mush all my food up and drink it through a straw after I broke my jaw.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.