撇 has different tones for different meanings: piě (3rd tone) for the stroke name, piē (1st tone) for 'to cast aside.' The stroke meaning is more commonly tested at HSK level.
usage
As a stroke name, 撇 (piě) is the left-falling stroke (丿), one of the basic strokes in Chinese calligraphy. 撇嘴 (piězuǐ) means to curl one's lip in disdain or contempt.
