The term 'target of a blood thinner' can be summarized by the crossword solution 'CLOT'. A CLOT is a mass of blood cells and proteins that forms when the body's natural clotting process is activated. Clots can form in the veins or arteries, and can cause serious health problems if they become lodged in the wrong place. Blood thinners are medications that are used to prevent clots from forming, or to dissolve existing clots. Therefore, the target of a blood thinner is a CLOT.