B

ba bow Bad boy
Submitted by Grace Palmer

ba bye Blanket
Submitted by JustPondering via mumsnet.com

baba Grandpa. 
Usually accompanied with another word to differentiate between grandpas. e.g. Baba Car and Baba Spain.
Submitted by George Leaney

babaloli Ravioli
Submitted by Madelyn Postman

babooge Tattoo
Submitted by Louisa Elliston

bam mom Grandmom 

Courtesy of answers.yahoo.com

bazzert Dessert
From babycenter.com
   
bee-bop Flip Flops
From mothering.com

beinghave Behave
From babycenter.com

belbow Elbow
From babycenter.com

bender Elbow
From babycenter.com

bednight Bedtime. 
e.g.'Time for bednight'
From mothering.com

bexxiff Breakfast
From mothering.com

biccits Biscuits
Submitted by Charlie Ambrose

big jig Biscuit
Submitted by Sara Jones

bing bing Dummy
Submitted by Ben Tucker

binoculators Binoculars
From babycenter.com

blambees Kitchen Tongs
From JustMommies.com

bob dada Bob the Builder
Submitted by Joanna Welfare

bocollol Bottle
Submitted by Joanna Welfare

bo-goes Bananas
Submitted by Julie Thomas
boos Spoon
From mothering.com

boo shoes A kitchen pot or pan, often accompanied with a kitchen utensil, usually a wooden spoon or masher.
Submitted by Emma Leaney

booteggings Burger King
Submitted by Scott Vaux-Nobes

booty Grapes
Submitted by Angharad Tan

brinkles Stubble/Beard
Submitted by Melanie Healy

brocalilli Broccoli 
Submitted by Diana Barnes

broccoli Properly
As in 'Sit broccoli'
Submitted by Madelyn Postman

bubba Biscuit
Courtesy of answers.yahoo.com

bubbadee Ladybird
Submitted by Amt Wadham

budda Dummy
Submitted by Scott Vaux-Nobes

buddha Umbrella
From mothering.com

buddy Dummy
Submitted by Will Miles

bumbunge Sponge Bob
Submitted by George Leaney

bumtits Crumpets
Submitted by Nikki Francis

busghetti Spaghetti
Submitted by Steve Nicholls

butter-buts Butterfly
From mothering.com