切片 (qiē piàn) is a verb-object compound meaning 'to slice (tissue) into sections' — 切 (to cut) + 片 (slice). It's a separable verb (离合词): when you need to add a quantity or duration, the object 片 separates, e.g. 切了三片 ('cut three slices'). This term is especially common in medical and laboratory settings for preparing tissue samples.