There are many common occupations that begin with the letter "j," including janitor, jailer, jeweler, jocky, judge, justice of the peace and journalist. In addition, less common occupations, such as judge advocate or Judge Advocate General, also begin with the letter "j."
Beyond the more obvious occupations that begin with the letter "j," there are a number of colloquial words describing vocations that also begin with the letter. For example, a jazzer, jazzbo or jazzman is slang for a serious jazz musician. A jacktar is another name for a sailor, and a jäger is a hunter. For a more encompassing word, jack-of-all-trades describes a handyman or multi-talented individual who can perform multiple tasks with proficiency. There are also three "j" words used to describe temporary or situational occupations, such as juror, jail house lawyer and joiner, a worker who constructs interior woodwork such as doors, molding or stairs.
There are also many "j" occupations that come to the language from another place or time. The British, for example, use the term jobber to describe a person who deals in stock exchange securities. Back in Medieval France and England, jongleurs were wondering minstrels who entertained others by reciting lyrical poetry and singing.