1. in a way that shows doubt or uncertainty about something
2. in a way that is questionable or of uncertain quality or honesty

Examples

• She looked at him dubiously when he claimed he had finished all his homework.
• The witness testified dubiously, changing his story several times.
• The restaurant’s health rating was dubiously low.
• He dubiously accepted the stranger’s offer of help.
• The company’s financial records were dubiously organized.
• She dubiously examined the used car before making an offer.