1. of a human, unstable, unsteady on one’s feet; of an animal, lame.
2. (also dotty in the dome) eccentric, odd; thus dottiness, eccentricity; dotty homestead, dotty house, a pyschiatric institution.
3. usu. constr. with preps. on/over, in love with, desirous of.
[late 19C–1920s] mad, eccentric.