Answer:

SEAL

Answer	Crossword Clue
SEAL	"Burp" the Tupperware
SEAL	Bering Sea swimmer
SEAL	Close hermetically

SEAL	Marine Land performer
SEAL	Shut tightly
SEAL	Yeats' country
SEAL	Hallmark
SEAL	Harp or elephant
SEAL	Pod member
SEAL	Barker at Sea World
SEAL	Emblem

SEAL	Letter closer
SEAL	Navy diver
SEAL	Whiskered critter
SEAL	Fin-footed mammal
SEAL	Navy elite
SEAL	Shut up
SEAL	Navy special ops acronym
SEAL	Prepare for posting

SEAL	Close tightly
SEAL	Circus barker
SEAL	Cachet
SEAL	Stamp of approval
SEAL	Close up
SEAL	Consumer protection
SEAL	Apply wax
SEAL	Navy commando

SEAL	Waterproof
SEAL	Guarantee
SEAL	Mammal with flippers
SEAL	Signet
SEAL	Approval shower
SEAL	Heidi Klum's ex
SEAL	.. of approval
SEAL	Make airtight

SEAL	Dollar-bill feature
SEAL	Emblem on the president's lectern
SEAL	It makes an impression
SEAL	Wax on an old letter
SEAL	Envelope closer