career

"The difference between a job and a career is the difference between forty and sixty hours a week" - Robert Frost

Indeed, I was just reading about this! See comments on careen, and also the following:

"In today's competitive business world, no one would be surprised to learn that career has its roots in horse racing. However, there may have been a time when one's career had more in common with a track than with a race. Career comes from the French word carrière, 'race course,' which entered Old French from Old Provençal carriera, 'street,' and goes back to carrus, the Latin word for a type of wagon. Carrus comes from Gaulish, the language of the Celtic tribes that inhabited the area that is now France both before and during the period of the Roman Empire. The Gaulish word is ultimately from the Indo-European root *kers-, 'to run,' which is also the source of the Latin verb currere, 'to run,' from which English ultimately gets such words as courier.

"In early use, career had such senses as 'race course,' 'a short gallop at full speed,' 'a rapid course,' and 'the moment of peak activity.' It appears that the sense 'a profession' originated in French carrière, which never acquired the English connotation of haste. Subsequent to the borrowing of English career in the 16th century, carrière came to mean 'the course of the stars and planets through the sky,' 'the course of one's life,' and 'the course of one's profession.' This ultimate sense became associated with the English word in the 19th century, and dotay stands appropriately alongside the native sense 'to rush.'"
--More Word Histories and Mysteries, From Aardvark to Zombie, from the Editors of the American Heritage (r) Dictionaries, 2006.

"Move headlong at high speed"

compare to careen - "Walk as if unable to control one's movements"