Sentence:  In normal operations, the rate of descent (or sink rate) will be approximately constant as the airplane approaches the runway. The objective of the <WSD>flare</WSD> is to reduce the vertical speed to an acceptably low value at the time when contact is made with the ground. ... Typically, the airplane will slow down a little in the <WSD>flare</WSD> and the touchdown speed will be about 3 to 5 kt less than the speed at the screen heightnb.... 
Meaning of the word marked with <WSD> tags:  The transition from downward flight to level flight just before landing.