Frequency: The word is one of the 1500 most common words in English.
Co. is used as an abbreviation for company when it is part of the name of an organization. ( BUSINESS )
...the Blue Star Amusement Co.
Co. is used as a written abbreviation for county before the names of some counties, especially in Ireland.
You use and co. after someone’s name to mean the group of people associated with that person. ( INFORMAL )
Wayne Hussey and co. will be playing two live sets each evening.
PHRASE : n-proper PHR