Significados de tight ligature em inglês

Whenever they feel a pain, they fasten a tight ligature round the part, thereby stopping the circulation, and easing the part immediately affected.

Their method of operation is to encircle the external genital organs with a tight ligature, and then sweep them off at one stroke.

Seeing, therefore, that the moderately tight ligature renders the veins turgid and distended, and the whole hand full of blood, I ask, whence is this?