Answer: her tendency to act without forethought
Explanation: In Act V, Scene III, of "Romeo and Juliet" by William Shakespeare, the tragic flaw of Juliet's character is her tendency to act without forethought. Juliet wakes up. Friar Laurence is there and tells her to leave the place. She sees Romeo dead and as there is no poison in the bottle, she kisses Romeo to absorb the poison from his lips. As there is no poison when she hears noise she grabs a knife and kills herself.