Which of the following Thai words means "to learn"?

The Thai word that means "to learn" is "เรียน." This term is commonly used in various contexts involving education, skills acquisition, or experience. For example, you might hear someone say "เรียนหนังสือ," which means to study in a formal educational setting. The root of the word emphasizes the act of engaging in the process of learning.

Looking at the other options, "กีฬา" refers to sports or physical activities, "หนัง" means a book or movie, and "เพลง" translates to song. Each of these words serves a distinct purpose and does not convey the concept of learning. Therefore, "เรียน" stands out as the only term that aligns with the meaning of "to learn."