To make someone feeling slightly frightened or worried about their ability to achieve something. (Cambridge Dictionary)
To overcome with fear; intimidate. (Dictionary.com)
To lessen the courage of; dishearten. (Dictionary.com)
If something daunts you, it makes you feel slightly afraid or worried about dealing with it. (Collins Dictionary)
To lessen the courage of: Cow, Subdue. (Merriam – Webster)
Make (someone) feel intimidated or apprehensive. (Oxford Dictionaries)
Why is marriage such a daunting task?
How to Get Started on an Incredibly Daunting Project.
Solutions to the most daunting, irritating and time-consuming household hassles.