Synonyms for Stopper:

n.

flip top, compartment, lip, cap, fill, overflow, full, lid, mouth. closure (noun)
seal, obstruction, fastener, choke, lock, closure.
plug (noun)
spile, bung, tap, stopple, plug, cork, spigot, stop, cover, lid, valve, fill.
stopper (noun)
plug, show-stopper, conversation stopper, stopple.

v.

contact (verb)
stopple.

Other synonyms:

cap. fill. stop up
plug.
Other relevant words:
stopple, conversation stopper, show-stopper, lid, bung, cap, fill.

Usage examples for stopper

  1. Colleville tried by a few jovialities to raise the temperature of the assemblage; but the coarse salt of his witticisms had an effect, in the atmosphere in which he produced them, of a loud laugh in a sick- chamber; and a mute intimation from his wife, Thuillier, and la Peyrade to behave himself put a stopper on his liveliness and turbulent expansion. – The Lesser Bourgeoisie by Honore de Balzac
  2. He had no choice but to walk up to the medicine bottle whose stopper was out. – Lonesome Town by Ethel and James Dorrance
  3. You put the stopper on to that intention. – The Dark Tower by Phyllis Bottome