2MHelective medicaltreatment is treatment that you choose to have, although you do not have to 〔治疗〕非必需的,可选择的
elective surgery such as hip replacements
髋关节置换术等非必需的手术
3.American EnglishAmE an elective course is one that students can choose to take, although they do not have to take it in order to graduate 〔课程〕选修的 → module
American EnglishAmESEC a course that students can choose to take, but they do not have to take it in order to graduate 选修课 → module
Examples from the Corpus
elective• This class is an elective, and so I chose it, and I chose to come.• Or is this just another blow-off elective, designed to pad the students' schedules?• A mixed group of students would be catered for by placing greater emphasis on electives.