Gloat
Gloat , intransitive verb
[Akin to Icelandic glotta to smile scornfully, German glotzen to gloat.]
To look steadfastly; to gaze earnestly; to gaze with passionate desire, lust, or avarice.
2.
To gaze with malignant satisfaction; to exult maliciously, sometimes also triumphantly, in another's loss or discomfort; -- usually in a bad sense.
In vengeance gloating on another's pain.