The word spatchcocking refers to the process of removing the
backbone and breaking the breastbone of a bird. The partially
boned fowl can then be spread open and flattened for cooking.
While similar to butterflying, the process of spatchcocking
implies the use of whole poultry rather than a single cut of
meat. It is believed that the word is derived from the term
"dispatch the cock." Spatchcocking a turkey, chicken, or any
other poultry results in a bird that takes up less oven space,
cooks more evenly and quickly, and is easier to carve. Source:
Flickr User thebittenword.com