What makes a winner in our monthly neologism contest? Ask the early bird. He knows how worms get snared. And now Catherine Nichols and Susan McLaughlin do, too.

Their answer to the December challenge was among the first 10 entries I opened up. That turned out to be a very good thing for Catherine and Susan, because two identical entries arrived soon after.

But under the rules of our contest, the first of identical entries to hit my mailbox is the winner. So onto the heads of Catherine and Susan went the crown -- and only condolences go to Ramona Sly of Chantilly and David A. Ames of Crofton.

This was the challenge that occasioned all the worm-catching:

The father is reading his newspaper in the den. The young child approaches. "Daddy," he or she says, "where do babies come from?" The Daddy puts down his newspaper, chokes softly and replies, "Go ask your mother." This phenomenon is called . . . .

The winning answer:

Sex Hedgeucation.

If that reads like the work of two wordsmiths, it's no accident. Our winners both edit scientific journals for the American Society of Hospital Pharmacists in Bethesda.

Catherine is a pharmacist by training. Susan is a blue-penciler by training. "She's the humanist, I'm the scientist," explained Catherine, over a sumptuous salmon victory lunch at Tragara in Bethesda.

The humanist-scientist team has been entering the neologism contest jointly ever since September. That month's challenge dealt with unfinished pills. It caught their pharmaceutical eyes.

The two editors hadn't previously come close to the winner's circle. But the third try was the charm. Hats off!

Plenty charming in their own right were this month's Almosts and Nearlies. Without further ado:

Dodge City: Al Toner of Arlington.

Daddy Fearest: Mary Lou McLain of Falls Church.

Child Whychology: Maude Freeman of Northwest.

Child Sighchology: Art Shaffer of Sringfield.

Poppin' the Question: Joseph A. Pappano of Northwest.

Mum's (or Mom's) the Word: Liz Munsen of Gaithersburg, Norbert Kockler of Alexandria, Joy Howard of Southeast, Allison P. Aul of Reston, Betty Brusco of Darnestown and Susan Milbrath.

Infant-Aside: Jack Reilly of Bethesda and Marie Anne Erickson of Braddock Heights, Md.

Obstetricks: Virgil Moore of Silver Spring.

To see if you were paying attention in Latin class, Pater No-Stir: Deborah Rinn of Arlington.

And another -- Mom Sequitur: Robert S. Goldfarb of Silver Spring.

Weasel Goes the Pop: Debbie Erickson of Arlington.

Paternity Scoot: John L. Cummings of Burke.

Cop-Out-u-Lation: Frances Gouled of Bethesda.

Cowardad: Bruce Learned of Bealeton, Va.

Fetal Attraction: Robert C. Gallagher of Falls Church.

Triplet Bypass: Garth Clark of Springfield.

Opt-to-Mom-ism: Jeff Covel of Arlington.

Paternitwitty: Pepper McGowan of Quantico.

Bouncing Baby Ploy: Debra L. Gregory of Manassas.

Dereliction of Daddy: Leonard F. Wheat of Alexandria.

Repro-Duck-Tion: Laura Stead.

Chickens and the Bees: Richard A. Ruth of Clinton.

Bye-Sexuality: Rosemary K. Brandus of Rockville.

Dadsterly Deed: Kevin Maclay of Lewisburg, Pa.

Saved by the Belle: Kelly Erno of Silver Spring.

Skirting the Issue: Mary L. Chipouras of Bethesda, Tim McDermott of Temple Hills, Ginger Burch of Waldorf and Sue Browning of Columbia.

Facts of Wife: Florence S. Orbach of Silver Spring, Eric Angell of Charlottesville, Dale Smith of Silver Spring, Frank M. Freeman of Charlottesville, Jim Fay of Arlington and Bob Ross of McLean.

Brush-Offspring: Bill Beckett (a former winner) of Bethesda.

Transparentcy: Miles Klein (another former winner) of East Brunswick, N.J.

The Birds and the Heebeejeebees: Christopher Barrett of Baltimore.

Mexican Handoff: Joe Welch of Harwich, Mass.

Sexcommunication: Sue Pierce of Rockville.

Stork Terror: Jack Melnick of Olney and Lisa Richards of Woodbridge.

Macho Do About Nothing: Raymond E. Newberry of Arlington.

Facts Evasion: Kelley Kraft of Northwest.

Pregnant Pause: Gloria H. Parloff of Bethesda, Clare Novak of Los Altos, Calif., and Valerie Hirsch of Silver Spring.

Chicken Pops: Wanda J. Williams of Capitol Heights.

Father Noes Best: Gary Wolcott of Arlington and Jean Maclay of Fort Washington (last month's winner).

Mom-entous Decision: Teddy Knight of Gaithersburg.

Ovoiding the Issue: Steve Sperling of Silver Spring.

Sexculpation: Judy Hallett of Bethesda.

And Stork Exchange: Trish Rosenberg of Timberville, Va.

Since there was so much interest in the world's longest three-letter word (memo to the IRS: I'm not talking about 'tax'), we'll stay with that subject for the January challenge. Here goes:

It's a Saturday night. You and your spouse have finally gotten the kids to bed. You've cleaned up the kitchen. You've finished fighting about money. So you start to get affectionate with one another. Ver-r-r-r-y affectionate with one another. Just as things are becoming especially personal, a voice is heard, from down the hall. It says: "Mommy! I want a drink of water!" This phenomenon is called . . . .

Sorry, but "homicide" will not win. However, if you choose the neologism that does, you'll win the usual prize: A free lunch with Levey, at a restaurant of your choice in or reasonably near Washington.

I'm afraid I can't promise the winner an interruption-free sex life, much as I might like to. The press may be powerful, but it's not that powerful.

Rules: You may enter as often as you like. Joint entries are perfectly all right. Your entries may be listed on one piece of paper or several. Entries become my property. Entries will not be accepted by phone nor will they be returned. All entries must bear a daytime and evening phone number. In case of duplicate entries, the entry I receive earliest will be the winner. In case of disputes, my ruling is final.

January entries must be postmarked by Jan. 30. Please mail entries to Bob Levey, The Washington Post, Washington, D.C., 20071.

CHILDREN'S HOSPITAL

The days dwindle to a precious few (11, if you're keeping score). If we're going to set a record in 1987-88, we need a precious few dollars from each person who has not yet contributed to our annual fund-raising drive.

Isn't this the day to sit down and write the check you've been meaning to write to the Hospital With The Built-In Deficit?

TO CONTRIBUTE TO THE CAMPAIGN:

Make a check or money order payable to Children's Hospital and mail it to Bob Levey, The Washington Post, Washington, D.C. 20071.