Malone (1790) read: 'So viperous slander.'
Mr Staunton proposes 'Thus calumny,' but in his text follows Capell.
'Malice' or 'Envy,' in the sense in which it is often used by Shakespeare, would suit the passage as well as 'Slander.'
Note XXIV.
IV. 2. 1—3. The second and third Quartos begin the scene thus:
'Ham. Safely stowd, but soft, what noyse, who calls on Hamlet?'
The fourth and fifth have 'softly' for 'soft.'
The Folios have:
'Ham. Safely stowed.
Gentlemen within. Hamlet, Lord Hamlet.