BET - A wager, an agreement between two parties that a stake (usually money) will be paid by the loser to the winner (the winner being the one who correctly forecast the outcome of an event).
BUT - Outside of.
LET - To allow to, not to prevent (+ infinitive, but usually without to).
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.
BELL - A percussive instrument made of metal or other hard material, typically but not always in the shape of an inverted cup with a flared rim, which resonates when struck.
BELT - A band worn around the waist to hold clothing to one's body (usually pants), hold weapons (such as a gun or sword), or serve as a decorative piece of clothing.
BLUE - Having a bluish colour shade.
BULL - The uncastrated adult male of domesticated cattle or oxen.
TELL - To count, reckon, or enumerate.
TUBE - Anything that is hollow and cylindrical in shape.
LUBE - Lubricant.
LUTE - A fretted stringed instrument, similar to a guitar, having a bowl-shaped body or soundbox.
BULLET - A projectile, usually of metal, shot from a gun at high speed.