Wiktionary
n. (context US English) A saltine; (context British English) a soda biscuit.
WordNet
n. unsweetened cracker leavened slightly with soda and cream of tartar
Usage examples of "soda cracker".
I handed him two alphabet blocks and part of a half-eaten soda cracker.
The plastic soda cracker had vanished down a sewer grating, gone on its long voyage home in the mysterious underground of Malesco.
The stone crushed his back with the sound of a breaking soda cracker.
Maybe it's just my middle-aged attitudes, but I tell you, most of the kids we hire in the Finance Department of Western Enterprises have the brains of a soda cracker.
She had been teetering on the edge of starvation, repelled by the sight and even the thought of food, stubbornly refusing to eat more than an occasional soda cracker or slice of bread, often gagging on even those bland morsels.