Used to express physical nearness, suggesting personal space is being shared. At the crowded concert, fans stood close up to the stage.
Pro Tip 2/3
Intimacy Hint
Implies a degree of intimacy or comfort when used to describe physical closeness between people. She felt so comfortable with him that she sat close up to him on the sofa.
Pro Tip 3/3
Space Invading
May be used negatively if someone enters your personal space without consent. He got close up to me in line, and I felt my personal space was invaded.