Pronunciation: [tə flˈʌʃ ˈʌp] (IPA) 
The correct spelling of the word is "to flush out," not "to flush up." IPA phonetic transcription for "to flush out" is /tuː flʌʃ aʊt/. This means that the word is pronounced with a long "u," followed by the sound of "f" and "l." The "u" is then followed by "sh" and "au" sounds, and finally by the "t" sound. The term "to flush out" means to force something out or to drive it away, often by using water or other fluids.
The term "to flush up" is an idiomatic expression which is commonly used to describe an action of startling or causing someone or something to leap or jump suddenly due to surprise, fear, or excitement. This phrase is often used to depict a sudden movement or reaction in response to an unexpected event or situation.
The word "flush" in this context means to startle or surprise somebody, causing a quick and sudden reaction. It conveys the idea of something or someone being caught off guard or taken aback. The additional term "up" is added to emphasize the rapid or abrupt jump, leap, or movement that accompanies the flushing.
The expression "to flush up" can be used to describe various scenarios where an individual or an animal is startled or jumps suddenly due to a sudden noise, surprise appearance, unexpected movement, or any other event that provokes an instant reaction. For example, when a person is suddenly scared by a loud bang, they might flush up and leap back in shock. Similarly, when a flock of birds senses danger, they may flush up and fly off instantly in a synchronized motion.
Overall, "to flush up" describes the sudden and instinctive reaction of being startled or surprised, leading to a quick jump or leap. This expression is commonly used to depict such situations in a vivid and descriptive manner.
