BUN - A small bread roll, often sweetened or spiced.
BUT - Outside of.
BUY - To obtain (something) in exchange for money or goods.
NUT - A hard-shelled seed.
TUB - A flat-bottomed vessel, of width similar to or greater than its height, used for storing or packing things, or for washing things in.
NUB - The innermost section of a chrysalis in a silk cocoon.
BULL - The uncastrated adult male of domesticated cattle or oxen.
NULL - A non-existent or empty value or set of values.
BUNT - The middle part, cavity, or belly of a sail; the part of a furled sail which is at the center of the yard.
BLUNT - Having a thick edge or point, as an instrument; not sharp.
BLUNTLY - In a blunt manner; without delicacy, or the usual forms of civility.