v. t. | 1. | To make stiff; to make less pliant or flexible; |
2. | To inspissate; to make more thick or viscous; | |
3. | To make torpid; to benumb. | |
v. i. | 1. | To become stiff or stiffer, in any sense of the adjective. |
Verb | 1. | stiffen - become stiff or stiffer; "He stiffened when he saw his boss enter the room" |
2. | stiffen - make stiff or stiffer; "Stiffen the cream by adding gelatine" | |
3. | stiffen - restrict; "Tighten the rules"; "stiffen the regulations" |