stiffen
transitive & intransitive verbTo make or become stiff or stiffer.
To become stiff.
To become less soft or fluid; grow thicker or harder; become inspissated: as, jellies stiffen as they cool.
To become steady and strong: as. a stiffening breeze.
To become unyielding; grow rigid, obstinate, or formal.
To become higher in price; become firmer or more unyielding: as, the market stiffens.
To make stiff.
To make rigid, constrained, formal, or habitual.
To make more thick or viscous; inspissate: as, to
To make stubborn or obstinate.