autem cackletub
obsolete Any general meeting place of dissenters of a given denomination of the (Christian) church; a conventicle. "Autem" is an obsolete slang word for church, and "cackletub" (a slang term for the pulpit of a church) here refers to a place where those who spill secrets ("cackle") gather. I entered into the autem cackletub with trepidation, for who knows what sort one may find in a place of unruly dissent.
cat in the meal-tub
obsolete A surprise attack or ambush; a hidden or unseen danger. Primarily heard in US, South Africa. Many people want to legalize marijuana but are in denial of the cats in the meal-tub that may come with doing so. The young political candidate waited like a cat in a meal-tub for his rival's sordid history to come to public attention.
tub of guts
A particularly overweight person. I used to be a tub of guts when I was in high school, but during college I really made an effort to slim down.
throw a tub to the whale
To create a diversion, in order to avoid a dangerous or unpleasant situation. No one can know that I'm here, so throw a tub to the whale while I sneak out the back door!