Adverb
extemporally (comparative more extemporally, superlative most extemporally)
In an extemporal manner.
She marking them begins a wailing note And sings extemporally a woeful ditty How love makes young men thrall and old men dote How love is wise in folly, foolish-witty Her heavy anthem still concludes in woe, And still the choir of echoes answer so. William Shakespeare