knead

v. squeeze, shape, blend (clay, dough, etc.); massage

Kneading is a process in the making of bread, used to mix together the ingredients and add strength to the bread. Its importance lies in the mixing of flour with water. When these two ingredients are combined and kneaded, the gliadin and glutenin in the flour expand and form strands of gluten, which gives bread its texture. The kneading process warms and stretches these gluten strands, eventually creating a springy and elastic dough. If the dough is not kneaded enough, it will not be able to hold the tiny pockets of air created by the leavening agent (such as yeast or baking powder), and will collapse, leaving a heavy and dense loaf.
See more at Wikipedia.org...

Verb
1. make uniform; "knead dough"; "work the clay until it is soft"
(synonym) work
(hypernym) manipulate
(hyponym) proof
(verb-group) cultivate, crop, work
2. manually manipulate (someone's body), usually for medicinal or relaxation purposes; "She rubbed down her child with a sponge"
(synonym) massage, rub down
(hypernym) manipulate
(entail) rub

(v. t.)
To work and press into a mass, usually with the hands; esp., to work, as by repeated pressure with the knuckles, into a well mixed mass, as the materials of bread, cake, etc.; as, to knead dough.
  

(v. t.)
Fig.: To treat or form as by kneading; to beat.
  

to prepare dough in the process of baking (Gen. 18:6; 1 Sam. 28:24; Hos. 7:4). Kneading-trough the vessel in which the dough, after being mixed and leavened, was left to swell or ferment (Ex. 8:3; 12:34; Deut. 28:5, 7). The dough in the vessels at the time of the Exodus was still unleavened, because the people were compelled to withdraw in haste.