observance
/əbˈzɜ:vəns; əb`zəvəns/ n
1 [U] ~ (of sth) keeping or observing (observe 2b) a law, custom, festival, holiday, etc （法律、 习俗等的）遵守, 奉行; （节日等的）纪念
the observance of school rules 对校规的遵守
the observance of New Year's Day as a public holiday 把元旦当作公众节日的习俗.
2 [C] (fml 文) act performed as part of a religious or traditional ceremony 宗教仪式; 传统庆典
religious observances 宗教仪式.