n. & v.
n. unfermented grape-juice; must.
v.tr. (stummed, stumming) 1 prevent from fermenting, or secure (wine) against further fermentation in a cask, by the use of sulphur etc. 2 renew the fermentation of (wine) by adding stum.
[ Du. stommen (v.), stom (n.) f. stom (adj.) dumb ]