In a sensible, realistic, or practical manner. For example, You can count on Tom not to get cheated in that deal; he has both feet on the ground, or Jean is a dreamer, but her husband is a man with his feet on the ground. There is a related phrase, have both feet on the ground, meaning “to be practical or realistic.” [Mid-1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.