To muster or summon all of one's voice, strength, courage, etc.; to exert or strain oneself to the utmost (often with difficulty).
彼は最後の力を振り絞ってスピーチを続けた。
He mustered his last bit of strength and continued the speech.
咳でかすれた声を振り絞って「大丈夫だ」と言った。
With a voice hoarse from coughing, he strained his voice and said, "I'm fine."
試験中、彼女は覚えている限りの知識を振り絞って問題に答えた。
During the exam she summoned all the knowledge she had and answered the questions.