学长在英文中可以称为"senior"。

"Senior" is the English term for addressing a senior or an older student. It is commonly used in educational settings to refer to someone who is in a higher grade or has been in the institution for a longer period of time. The term "senior" is used to show respect and acknowledge the higher status or experience of the individual.In addition to "senior," there are other terms that can be used to address a senior in different contexts. For example, in a professional setting, "senior" can be combined with the person's job title, such as "senior engineer" or "senior manager." It is important to note that the specific term used may vary depending on the cultural and organizational context.Overall, addressing a senior in English as "senior" is a common and respectful way to acknowledge their higher status or experience.