Meaning of “strained” - Learner’s Dictionary

strained

adjective uk us /streɪnd/
NOT RELAXED

showing that someone is nervous or anxious:

We had a rather strained conversation.
DIFFICULT

If a relationship is strained, problems are spoiling that relationship:

Relations are still strained between the two countries.
They have a rather strained relationship.

(Definition of “strained” from the Cambridge Learner’s Dictionary © Cambridge University Press)