Hum and haw
Definition 1 of 1
Pro Tip 1/3Colloquial Use
Used more in casual speech and not in formal writing; suitable for everyday conversations. 
When asked about his travel plans, Mike hummed and hawed, avoiding a direct answer.
Pro Tip 2/3Indecision
Implies a person can't decide quickly, often due to uncertainty or lack of confidence. 
She hummed and hawed over the menu before finally picking a dish.
Pro Tip 3/3Frustration Cause
Can express or lead to frustration in others who are waiting for a decision. 
His tendency to hum and haw frustrated the team, as deadlines approached.