Secret application, perhaps
Secret area of anatomy?
Secret assembly
Secret assignations
Secret attachment, for short
Secret author: Abbr.
Secret bit of knowledge
secret brotherhood
secret ceremony
secret chamber in an ancient Egyptian tomb
secret Chinese society
Secret Chinese society, in the U.S.
Secret clique
Secret code
Secret collection
Secret collector
Secret collectors
Secret competitor
Secret couple, in gossip
Secret DC headquarters
Secret decoder ring?: Abbr.
Secret deposits
Secret devices
Secret diet-breakers
Secret discovered by a woodcutter
Secret dish in "Sweeney Todd"
Secret doctrine
Secret employer, maybe
Secret encounter
Secret ending?
Secret engagement
Secret event of '45
Secret Exit
secret exit Magician Amazing
Secret exit, maybe
Secret exit, perhaps
Secret file
Secret finish
Secret follower
Secret for some superheroes
Secret formula
Secret fraternity
Secret fraternity member
Secret get-together
Secret get-togethers
Secret govt. group
Secret gp.
Secret group
Secret grp. since 1947
Secret headquarters for Bruce Wayne
Secret hideaway
Secret hiding place
Secret hoard
Secret hoards
Secret holder
Secret hot date
Secret identity
Secret identity of "The Amazing Amazon"
Secret identity of Dick Grayson
Secret identity of the Green Hornet and the Lone Ranger
Secret identity Preserver Fossil
Secret identity?: Abbr.
Secret indicator
Secret information
secret information about an enemy
Secret insiders
Secret intelligence service operative
SECRET intrigue
Secret keeper
Secret keeper, to the teller
Secret key to admission
Secret knowledge
SECRET language
Secret Language columnist William
Secret language device
secret language used by some traveling people in Britain and Ireland
Secret languages
Secret lingo
Secret listeners
Secret listening devices
Secret locks?
Secret looks
secret love affair
Secret love affairs
Secret lover
secret marriage
secret massage system
Secret matters
Secret Meeting
secret meeting
Secret meeting between lovers
Secret meeting places
Secret meetings
Secret meetings with the queen?
Secret message
Secret message letters
Secret message medium
Secret message technique ... and a hint to four puzzle clues
Secret metaphor
Secret mike
Secret military mission ... or a hint to the circled letters in this puzzle?
Secret moniker
Secret motive
Secret motives
SECRET movement (pol.)
Secret observer's opening
Secret observers
Secret of Glen Bell's success
secret of God
secret of great comedy
Secret of many a redhead
Secret of some redheads
Secret of the ___ (Yma Sumac movie)
Secret of the vain, perhaps
Secret one
Secret ones do missions
Secret or "free" follower
Secret or cleaning thing
Secret or illegal
secret or mysterious
Secret or Sure
Secret order member
Secret org.
Secret partnership
Secret passage, perhaps
Secret passers
Secret person who writes a love note
SECRET place
Secret place where drunkard might be found?
Secret place?
Secret places
Secret plan
secret plan to do something illegal or wrong
Secret planning between people to do something that is illegal or unethical
Secret plans
Secret pledge in each of the four longest Across answers
Secret plot
Secret plot found in 17-, 26-, 44- and 55-Across
Secret police before the wall fell
Secret police dissolved during German reunification
Secret police of the former German Democratic Republic
Secret police who fell with the Berlin Wall
Secret political clique
Secret political group
SECRET procedure
Secret pros
Secret publishing and distribution of literature banned by state of USSR
Secret relationship
secret religious rites
Secret rendevous
Secret rendezvous
Secret rendezvous point
Secret repository
Secret retreat
Secret retreat hidden in this puzzle's nine longest answers
Secret retreats
Secret revolutionary force
secret rites
Secret rival
Secret rival?
Secret romance
Secret romantic meeting
Secret Santa gift
Secret Santa season
Secret scheme
Secret schemers
Secret schemes
Secret schemes within a powerful group
Secret script
Secret self
Secret sentences
secret sequences
secret service
Secret Service accessories
Secret Service after prince over Virginia
Secret service agent on "Warehouse 13"
Secret Service agent, often
Secret Service agent, until recently
Secret Service agent's accessory
Secret Service agent's accessory, at times
Secret Service agent's accouterment
Secret Service agent's weapon
Secret Service concern
Secret Service dossier
Secret Service eyewear
Secret service operatives
Secret Service role
Secret Service title
Secret Service worker
Secret service, quite possibly
Secret Service's charge: Abbr.
Secret sharer
Secret sharer, slangily
Secret sign
Secret signal
Secret societies
secret society
SECRET society devoted to occult lore
Secret society in Chinatown
Secret society in Dan Brown's "Angels & Demons"
Secret society invoked in many conspiracy theories
Secret society member
Secret society member, perhaps, briefly
Secret society members
SECRET society of the Ribbonist type
secret society rule
Secret society's secret
Secret source
Secret spiller
Secret spiller's intro
Secret spillers
Secret spot
Secret spot?
Secret spots?
Secret Squirrel, for one
Secret stash
Secret stat, sometimes
Secret stealer
Secret Stock
Secret stockpile
Secret storage spot
secret store
secret store of valuables or money
Secret stores
Secret stuff
Secret suffix
Secret supplies
Secret supply
secret symbol
secret symbol of letters
Secret sympathizers
secret systems of writing
Secret target
Secret target?
Secret targets
Secret targets?
Secret thieves of slang
Secret things
Secret to the max
Secret trove
Secret U.S. govt. group
Secret union former
Secret vocabulary
Secret vote
Secret W.W. II agcy.
Secret watcher
Secret weapon
Secret Window star, 2004
Secret words
Secret words?