Origin of the term "grounded"

What is the origin of the term "grounded", as in "it keeps me grounded"? Does it simply come from the ground itself, which is to say keeping one's feet on the ground, or does it refer to "ground" in the electrical sense?

The word grounded is from (adj.) "learned," late 14c.; "firmly fixed or established," 1540s, past participle adjective from ground (v.). Electrical sense is from 1889. Meaning "having been denied privileges" is from 1940s. Dickens had room-ridden "confined to one's room."

It's an early construction term:

GROUND, to fetor lay a thing on the ground; to lay a ground-work; to take for a foundation ; ro raise an argument upon.

GROUNDED (of gjnunb.oa*.) sounded, built or resting upon, sustained by.

GROUNDLESS (?Jiun?lear, 5a*.) without ground, foundation or reason.

-An universal etymological English dictionary ... v. 2. Bailey, N. (Nathan), d. 1742.