A skald (there's a variant spelling "scald" also, but frankly
I've seen skald much more often) is a Scandinavian "poet" of the
Viking age, though perhaps "bard" might be a more accurate
equivalent. Skalds were primarily performers, not writers, though
some of their poetry has survived in written form.
Skaldic poetry was usually spoken, not chanted or sung, and the
skald held a semi-privileged position at court in that skalds were
generally allowed (and even encouraged) to speak harsh truths to
those in positions of power.