This is the 809th most frequent Chinese word.
先生
"先生" means "Mr.", "sir", "gentleman", or "teacher".
In this sentence, '先生' is used as a respectful title referring to an adult male, similar to 'Mr.' in English.
这位王先生是我们的老师。
Mr. Wang is our teacher.
Here, '先生' is used to mean 'husband' in a familial context, referring affectionately to one's spouse.
我的先生喜欢喝咖啡。
My husband likes to drink coffee.
In this case, '先生' is used as a polite address for an unknown adult male, similar to 'sir' in English.