to remove the long, black thread from a prawn (= a small sea creature eaten as food) or similar sea food

Devein the shrimp and place them in a shallow frying pan. 给虾去泥肠线，放在一个浅煎锅中。

De-vein the prawns with a sharp knife by making a cut along the back. 用一把锋利的刀沿背部划一刀，给虾去泥肠线。

to remove the part that is not eaten in the middle of some vegetables

Devein the chillies and remove the seeds. 辣椒去芯，拿掉种子。

De-vein the kale, then coarsely chop the leaves. 给羽衣甘蓝去芯，然后粗略地将叶子切碎。