deed poll

Từ điển Oxford Advanced Learner 8th

ˈdeed poll BrE NAmE noun uncountable, singular (BrE)
a legal document signed by only one person, especially in order to change their name
•Smith changed his name by deed poll to Jervis-Smith.

Word Origin:
[deed poll] late 16th cent.: so named because the parchment was “polled” or cut cleanly, not indented at the edges as in the case of a deed made by two parties.