Adjective

(er)

Dizzy, feeling dizzy or unsteady and as if about to fall down.

The man became giddy upon standing up so fast.

Causing dizziness: causing dizziness or a feeling of unsteadiness.

They climbed to a giddy height.

Lightheartedly silly, or joyfully elated.

* {{quote-book, year=1905, author=

, title= , chapter=2 citation , passage=Miss Phyllis Morgan, as the hapless heroine dressed in the shabbiest of clothes, appears in the midst of a gay and giddy throng; she apostrophises all and sundry there, including the villain, and has a magnificent scene which always brings down the house, and nightly adds to her histrionic laurels.}}

The boy was giddy when he opened his birthday presents.

(archaic) Frivolous, impulsive, inconsistent, changeable.

* 1599 ,

In brief, since I do purpose to marry, I will think nothing to any purpose that the world can say against it; and therefore never flout at me for what I have said against it, for man is a giddy thing, and this is my conclusion.

* 1784 , , Tirocinium; or, A Review of Schools

Young heads are giddy and young hearts are warm,

And make mistakes for manhood to reform.

Adjective

(en adjective)

Exhibiting unsoundness or disorder of mind; not sane; mad; deranged in mind; delirious; distracted.

* '>citation

What is the cause of insanity?
Nobody can answer such a sweeping question as that,
but we know that certain diseases, such as syphilis, break
down and destroy the brain cells and result in insanity. In
fact, about one-half of all mental diseases can be attributed
to such physical causes as brain lesions, alcohol, toxins,
and injuries. But the other half—and this is the appalling
part of the story—the other half of the people who go in-
sane' apparently have nothing organically wrong with
their brain cells. In post-mortem examinations, when their
brain tissues are studied under the highest-powered micro-
scopes, they are found to be apparently just as healthy as
yours and mine.
Why do these people go ' insane ?

Used by, or appropriated to, insane persons; as, an insane hospital.

Causing insanity or madness.

Characterized by insanity or the utmost folly; chimerical; unpractical; as, an insane plan, attempt, etc.

* , chapter=16

, title= The Mirror and the Lamp , passage=The preposterous altruism too!