Originally, "A/S/c", with "A" the arrival process, "S" the distribution of service time required, and "c" the number of servers.

(mathematics) The use of a mathematical notation in a way that is not formally correct but seems likely to simplify the exposition or suggest the correct intuition.

plural of abuse of notation

(derogatory) being out of key

(derogatory) the state of being out of key

(humorous) Used to point out that somebody is in a state of psychological denial.

Alternative form of all that glitters is not gold

(obsolete) An exclamation mark.

To make no difficulty of (a given occurrence); to consider (a particular occurrence) as trifling or unimportant. / To fail to understand.

(sometimes humorous) Someone who is more intelligent, talented, or emotionally complex than might be assumed.