say it: DAH-tee
dotty is an adjective meaning "informal or slang terms for mentally irregular". It carries 2 recorded senses.
intensely enthusiastic about or preoccupied with
“crazy about cars and racing”
“they are dotty about each other”
“gaga over the rock group's new album”
colloquialism
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for dotty come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.