Cautious; restrained: We view these changes with guarded optimism. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "guarded" in a sentence
"She glanced at Jared, her expression guarded, then smiled at the other girls."
"“What is it?” he asked, studying her closely, his expression guarded."
"She then focused on her brother, her expression guarded."