adjectivedialect, informal US, Midlands English
1Of a lawyer, preacher, or other professional: lacking skills or training, incompetent; unscrupulous, dishonest; (also of a preacher, chiefly in African-American usage) itinerant.
2Made or done hastily, clumsily, or unskilfully; shoddy, botched; makeshift, thrown-together.
Apparently rare before the late 20th century.
Mid 19th century; earliest use found in The Congressional Globe. Probably from Jack + legged, as an alteration of jackleg.