Mushmouth American slang
Someone who does not or is unable to express their feelings or ideas clearly.
Whenever I don't have enough sleep, I become a mushmouth.
I felt so ashamed of myself for being a mushmouth.
If I hadn't been a mushmouth, I would have been chosen for that position.
This slang dates from the mid 19th century.
Stupid or crazy
He is definitely not the full shilling when wearing a thick coat in this sultry weather.