1. Having in the head a sensation of whirling or reeling about; having lost the power of preserving the balance of the body, and therefore wavering and inclined to fall; lightheaded; dizzy. By giddy head and staggering legs betrayed. (Tate)
2. Promoting or inducing giddiness; as, a giddy height; a giddy precipice. Upon the giddy footing of the hatches. (Shak)
3. Bewildering on account of rapid turning; running round with celerity; gyratory; whirling. The giddy motion of the whirling mill. (Pope)
4. Characterised by inconstancy; unstable; changeable; fickle; wild; thoughtless; heedless. Giddy, foolish hours. Rowe. Giddy chance. Dryden. Young heads are giddy and young hearts are warm. (Cowper)
Origin: oe. Gidi mad, silly, as. Gidig, of unknown origin, cf. Norw. Gidda to shake, tremble.