Sentence:  She took a swallow of milk and made a face. "This milk is <WSD>blinky</WSD>."/ Mrs. Willet frowned. 'It shouldn't be. I just got it yesterday." She opened the top of the icebox and looked into the ice compartment. She groaned. "The block of ice I got yesterday is almost melted." 
Meaning of the word marked with <WSD> tags:  Of milk: turned somewhat sour.