casual [kazh-oo-uhl] - adjective. 
Origin: 1325-75; ME > L casualis, equiv. to casu(s) case 1 + -alis -al 1 1. happening by chance; fortuitous. 2. without definite or serious intention; careless or offhand; passing Once again, Gina Sapiro will be holding three "Dean's Summer Casuals" in her office, CAS 106, on Tuesday, June 5; Wednesday, July 11; and Wednesday, August 1, all from 4 to 5 p.m. These are informal gatherings for faculty who happen to be working on campus during these summer days. No need to come to campus specially to attend. As always, they are completely informal times to share a glass, catch up, and schmooze.