This is the 9546th most frequent Spanish word.
anónimo
Anonymous.
In this sentence, 'anónima' is used as an adjective to describe the letter, indicating its lack of identifiable origin.
Recibí una carta anónima ayer por la tarde.
I received an anonymous letter yesterday afternoon.
Here, 'anónimo' is an adjective describing the state of the author, expressing their desire to keep their identity undisclosed.
El autor del poema quiso permanecer anónimo.
The author of the poem wished to remain anonymous.
In this context, 'anónima' is an adverbial expression describing the manner in which the survey was published, emphasizing the focus on anonymity.