strained          
adjective uk/streɪnd/ us/streɪnd/
 (关系)紧张的,恶化的
If a relationship is strained, problems are spoiling it.
  Relations between the two countries have become strained (= difficult) recently. 最近两国关系变得紧张起来。 
  紧张的,焦虑的,神色不安的
showing that someone is nervous or worried
  She was looking strained and had dark circles beneath her eyes. 她显得焦虑不安,眼睛下面有了黑眼圈。 
 Jean felt uncomfortable but managed to force a strained smile. 琼觉得不舒服,但仍然勉强挤出了一丝笑容。