stiffen/ 'stɪfn /

1.vi.[person] [ body+] 
变僵直

2.vi.[muscles] [ joints+] 
(also: stiffen up) 变僵硬

3.vi.[attitudes] [ behaviour+] 
变得坚定

4.vt.[+cloth] 
使变挺

5.vt.[+attitude] [ behaviour] 
加强