plighting one's troth 许下婚约
plighting allegiance 宣誓效忠
A: Is this ceremony for plighting their faith?
A：这个仪式是为了宣誓效忠吗？
B: Yes, it is a formal act of plighting loyalty.
B：是的，这是一个正式宣誓效忠的行为。
1) 许下誓言
2) 缔结婚约
3) 做出庄严承诺
1. 许诺；缔结
verb (present participle)
1. Making a solemn pledge or promise, often used in formal or literary contexts.
Synonym: pledging, vowing