shy — nervous or uncomfortable around other people; showing a lack of confidence

a young student stands at the edge of the cafeteria holding their lunch tray, looking down at their feet with hunched shoulders. Their body is turned slightly away from the crowded tables where other students are sitting and laughing together. The student takes a small hesitant step toward an empty table in the corner instead of approaching the groups. Other students at nearby tables are chatting and gesturing enthusiastically while completely unaware of the lone student. The student's face shows uncertainty and nervousness about joining any of the social groups. someone being nervous and uncomfortable around other people, displaying a lack of confidence in social situations