| stiffen penalty | 4.94 | Would have stiffened penalties for pet theft. | ||
| stiffen resolve | 2.90 | A feeling that stiffened her resolve. | ||
| stiffen resistance | 0.92 | It also could stiffen their resistance, however. | ||
| stiffen sanction | 0.79 | The party stiffened its sanctions against Deuba on Sunday. | ||
| stiffen competition | 0.72 | Wheat prices tumbled amid new signs of stiffening global competition. | ||
| stiffen punishment | 0.72 | Sen. Larry Craig introduces a bill to stiffen punishments for spiking trees. | ||
| stiffen rule | 0.53 | Since then, the rule has been stiffened. | ||
| stiffen sentence | 0.46 | Prosecutors asked the Supreme Court to stiffen the sentences. | ||
| stiffen spine | 0.46 | The Democrats also need to stiffen their spines. | ||
| stiffen demand | 0.39 | The Forum for Democracy, a loose union of opposition groups, stiffened those demands on Friday. | ||
| stiffen law | 0.39 | Smith dismissed criticism of efforts to stiffen immigration laws. | ||
| stiffen requirement | 0.39 | It also plans to stiffen its requirements for all future drivers. | ||
| stiffen warning | 0.33 | His death prompted the embassy to stiffen a warning against using street taxis in the crime-plagued Mexican capital. | ||
| stiffen control | 0.26 | The text aims to stiffen copyright controls by introducing a licencing requirement for the production, export and import of compact discs. | ||
| stiffen regulation | 0.26 | The aviation agency is trying to stiffen those regulations. |