Referring Clues

• Japanese plane of W.W. II
• Worst possible score
• Round number
• No-show's score
• Abysmal test score
• Worst possible test score
• Two before two?
• One of 50
• Zilch
• Definitely a flunking score
• Ground ___
• "Beetle Bailey" boob
• Home (in on)
• Goose egg
• Absolute twit
• A definite F
• Nil
• Kind of tolerance
• Horrible grade on a test
• Round number?
• Nada
• Cipher
• Nobody, slangily
• Hardly Mr. Personality
• Reset figure
• It's nothing at all
• Part of binary code
• Abysmal grade
• Bubkes
• Number of tricks in a nullo
• Loser
• Complete drip
• "Beetle Bailey" soldier
• Much-repeated part of binary code
• A round number ends in it
• It turns a hundred into a thousand
• Total loser
• Number of calories in water
• Absolute nobody
• Nothing
• It's usually a losing score
• It may precede population growth
• Mostel of "The Producers"
• Part of ZPG
• None
• Unsigned point on a number line
• Freezing point of water, on the Celsius scale
• Speedometer's lowest reading
• One of six in 1,000,000
• Love, in tennis
• Lowest speedometer number
• Zip
• Complete bomb on a test
• Nobody
• Absolute ___ (bottom of the Kelvin scale)
• Number of items in a null set
• Character in "Beetle Bailey"
• Cheater's score, if caught
• Dog in the comic strip "Little Annie Rooney"
• Additive identity element
• One of a hundred in a googol
• Number that's neither positive nor negative
• "Beetle Bailey" nonintellectual
• Score for a gutter ball
• One of a googol in a googolplex
• It's not used in standard sudoku puzzles
• It's an indeterminate form when raised to its own power
• Gene's costar in "The Producers"
• One out of 10?
• Value of tens and face cards in baccarat
• Maria Sharapova's love?
• Sugar-free Coca-Cola variety
• Roulette number that loses on bets of both even and odd
• The year that wasn't?
• Bit of binary code
• Home (in)
• 49-Across number, maybe
• Reset, as an odometer
• Freezing point, on the Celsius scale
• Coldest possible temperature on the Kelvin scale
• You can't divide by it
• Blank tile value, in Scrabble
• Friend of Beetle Bailey
• Goose egg, in sports
• 48 Across less than 48 Across
• It's nothing
• Little Annie Rooney's dog
• Reset, with "out"
• Nothing at all
• Speedometer digit
• Beetle Bailey's pal
• Coldest temperature on the Kelvin scale
• Centigrade freezing point
• Love, to Venus?
• Chilling reading
• Mayan mathematical innovation
• Nonentity
• It's nothing, really
• "Beetle Bailey" simpleton
• 0
• World dodo population
• Centigrade's freezing point
• Reset
• Sum of opposites
• -
• Reset, with "out"
• Part of a shutout score
• Number of remaining dodo birds
• Coke ___
• Reduce to nothing
• Operator's number?
• Worthless sort
• Half of 10?
• Half of ten
• Half of ten
• Celsius freezing point of water
• Number line center
• Japanese plane
• Round figure?
• Winning score in darts
• Binary digit
• Celsius equivalent of 32 degrees Fahrenheit
• Diddly-squat
• Celsius freezing point
• Diddly
• Nothing, in a sports score
• Less than one
• It means nothing
• Naught
• One goes after it
• Number that is neither positive nor negative
• It may be absolute
• Complete loser
• Squat
• Number that shouldn't be a denominator
• Lowest of the low?
• 3-2-1 follower
• Open love?
• Centigrade freezing point of water
• One minus one
• "___ Dark Thirty"
• Nothing at Wimbledon
• Not a one
• Shutout score feature
• Terrible test score
• Zippo
• Celsius temperature at which water freezes
• Focus, with "in"
• Skipped-over year
• Green roulette bet
• Loser, informally
• "Beetle Bailey" blockhead
• Dismal attendance count
• Abysmal score
• 15 minus 15
• Cold temperature
• 32° Fahrenheit, in Celsius
• Today's dodo count
• MapMyWalk starting point
• It's less than one
• Nothing for Mostel?
• Nothing is included with prize rosette
• Nought
• Sucky attendance count
• Number in the Cookie Monster song "They Not Take That Away From Me"
• Word appearing before or after each word in the long theme entries
• Nothing - certainly not a hero!
• Two minus two
• Unknown tail-ender in disgrace, run out for 0
• Cross about her lacking aspiration in love
• Less than one hour for action
• The meaning of love
• Candy bar covered with a layer of white fudge
• See 22
• Plane in the Pearl Harbor attack
• The kind of tolerance that means nothing
• Love, as symbolised by something like ring
• With 5-Down, "The Producers" actor
• *With 70-Across, 2012 Best Picture nominee
• Number of times Garbo was married
• Japanese fighter plane
• Rock bottom
• Australia's uprising about Queen's duck
• Nil, nothing
• Freezer on? There's nothing in it!
• Love to frequent boozer occasionally
• At the end endless love comes to nothing
• Cross about leading member of the Establishment
• Nothing for Mostel?
• Round number?
• It's not even one
• Integer between -1 and 1
• ZPG part
• Nothing amount
• Gutter ball's pin count
• Goose egg, so to speak
• "The big doughnut"
• Odometer's initial reading
• One of three in the Y2K year
• Any digit in a googol after the first one
• 64-Across minus 64-Across
• The "x" in Euler's Identity: e^(i*pi) 1 = x
• Worst possible grade
• Beetle Bailey's dimwitted pal
• ___-g
• Test score for a cheater, if caught
• Number line’s midpoint
• Lowest grade
• Digit in binary code
• Unusable divisor
• None at all
• Lowest score, often
• ___ tolerance
• "Holes" character with a numerical nickname
• Very bad visibility and it's terribly cold
• Worst possible mark on a test
• Not even one
• Olive oil's carb count
• Undefeated team's loss total
• Memorable Mostel
• Any number minus itself
• Absolute ___ (coldest possible temperature)
• Score of a shutout
• Freezing point in Celsius
• It doesn't mean a thing
• Net emissions target
• From ___ to hero
• It lacks value
• Number resembling an egg
• Jack Skellington's ghost-dog
• It's not even one?
• Actor Mostel
• 67 minus 67
• Extremely cold temperature