What's Happening in Erie County. 1  September 1 - September 30 : Agricultural Districts Open Enrollment Period. 2  September 4 : Erie County Government offices are closed today. 3  September 5 : Justice Assistance Grant (JAG) Public Notification - Fiscal Year 2017.
Definition. 1  As a noun, the common definition of chemical is a substance that is produced or used in a process (reaction) involving changes to atoms or molecules. 2  As an adjective, chemical means of or pertaining to chemistry.
Wiktionary (0.00 / 0 votes) Rate this definition: chemical (Noun). Any specific chemical element or chemical compound. chemical (Noun). An artificial chemical compound. I color my hair with henna, not chemicals. chemical (Noun). An addictive drug.