Someone who's scholarly is a serious student. You can describe your studious friend who's always working on a research paper or reading a huge book as scholarly.
Use the adjective scholarly when you talk about a person who is focused on learning — in other words, a scholar. You can also describe things that relate to studying or knowledge as scholarly, like a scholarly article in a journal or a scholarly atmosphere in a library. The Old English word scolere, or "student," is the root of both scholar and scholarly, from the Latin word for school, schola.
adj characteristic of scholars or scholarship
characterized by careful evaluation and judgment
appealing to or using the intellect
showing intellectual penetration or emotional depth
academic, donnish, pedantic
marked by a narrow focus on or display of learning especially its trivial aspects
characterized by diligent study and fondness for reading
having or showing profound knowledge