Someone who is eligible to do something is qualified or able to do it, for example, because they are old enough.
entitled , qualified
ineligible
Almost half the population are eligible to vote in today's election.
将近一半的居民有资格在今天的选举中投票。
You could be eligible for a university scholarship.
你也许有资格获得一份大学奖学金。
An eligible man or woman is not yet married and is thought by many people to be a suitable partner.
He's the most eligible bachelor in Japan.
他是日本最令人中意的单身汉。