Initialism of adjacent channel selectivity.
"The acs gathered in the conference room to discuss the upcoming academic year's budget."
plural of ac
In plain English: ACS is an abbreviation for Advanced Chemistry Students, which refers to a specific high school chemistry course designed for students who want more challenging science classes than regular chemistry offers.
"The university has established three new academic centers to support research in renewable energy."
Initialism of Australian Computer Society.
"Many students joined the acs to network with other professionals in the field."