The noun 仪式 (yíshì) means 'ceremony' or 'ritual.' It refers to a formal event or series of acts performed on a special occasion, such as 命名仪式 (naming ceremony) or 开幕仪式 (opening ceremony). It is used in both cultural and official contexts.
毕业仪式定在下周六举行。
bìyè yíshì dìng zài xià zhōuliù jǔxíng.
The graduation ceremony is scheduled for next Saturday.
他们举行了简单而隆重的开幕仪式。
tāmen jǔxíng le jiǎndān ér lóngzhòng de kāimù yíshì.
They held a simple yet grand opening ceremony.
婚礼仪式非常感人,很多人都哭了。
hūnlǐ yíshì fēicháng gǎnrén, hěn duō rén dōu kū le.
The wedding ceremony was very moving, and many people cried.