Answer
Non-emigrant witness refers to Akhmatova's decision to remain in Russia despite the political turmoil and oppression during the Soviet era. Unlike many other intellectuals and artists who chose to emigrate, Akhmatova stayed in her homeland and courageously used her poetic voice to document the sufferings and injustices faced by the Russian people under Stalin's regime. Her unwavering presence and commitment to her country earned her the title of "non-emigrant witness."