Sentence:  “No, no,” cried lady Anna, in trepidation, “leave him—let him go.” / Lennard unloosed his hold for a moment; and regarding her ladyship with a look of jealous anger, he stood irresolute. / “Leave him,” <WSD>interjoined</WSD> Wentworth. “He has abused the privileges of a social meeting, by venting the preconcerted acumen of a malicious nature; he is beneath your contempt.” 
Meaning of the word marked with <WSD> tags:  To say by way of interruption, to interject.