In dictionaries:
thin on the ground
Scarce, few in number available.
thick on the ground
Abundant, plentiful in specific area.
had feet firmly planted on the ground
Grounded, realistic in expectations, stable.
has feet firmly planted on the ground
Realistic, practical, stable, sensible, grounded.
have both feet on the ground
Practical, realistic in attitude, approach.
have feet firmly planted on the ground
Grounded, realistic perspective and approach.
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