Comparative evidence

steu̯n, teu̯n

• OE stunian ‘crush’, ‘resound’, ‘roar’, ‘impinge’, ‘dash’ (Hall 1916: 280);

1) ‘crash’, ‘make a loud sound’; 2) ‘strike with a loud sound’, ‘crash’, ‘dash’; 3) later texts: ‘confound’, ‘astonish’, ‘stupefy’ (Bosworth, Toller 1898: 930)
King Alfred’s Anglo-Saxon version of the metres of Boethius, metre 26, line 58: (stearc storma gelac;) stunede sio brune ẏð wið oðre “one dark wave dashed against the other” (Bosworth, Toller 1898: 930), “the dusky wave beat on another” (Fox 1885: 114).

• MHG stunen, stunden ‎‘drive’, ‘push’, ‘knock’, ‘strike’

• MG staunen ‎ ‘to be astonished’, ‘be amazed’, ‘marvel at’

References

Bosworth, Toller 1898 = J. Bosworth, T. Toller, 1898. An Anglo-Saxon Dictionary. Oxford university Press.
Fox 1885 = King Alfred’s Anglo-Saxon version of the metres of Boethius with an English translations and notes. By rev. S. Fox. London, 1885.
Hall, J. 1916. A concise Anglo-Saxon dictionary. 2nd edition. MacMillan.