Alienate, depending on the context, can either mean to annoy somebody and thus earn their displeasure, or to distance a person.

Examples:

The below examples are in the context of irritating somebody:

"Do not leave your dishes in the sink, lest you alienate your housemates!" - here, alienate means to annoy or aggravate; by leaving dishes in the sink, which your housemates dislike, you risk displeasing/alienating them.

"The misogynist comments made by the Prime Minister alienated his female supporters."

Then there is the other meaning, and an example sentence may be:

"Living in a foreign country and unable to speak the language, I feel so alienated."

The person is having difficulties assimilating and hence feels estranged.

I hope the above makes it clear?

Thanks, sir

An alien is someone not from the same place. So to alienate someone is to do something that means that they do not consider themselves of the same place, or the same mind, or friends. . They all drank coffee in the cafe each morning. When she stopped drinking there, she alientated herself from them by not seeming one of the group anymore. . The boss's refusal to allow leave for compassionate reasons tended to alientate the workers.