Trimaine Williams has one of those jobs that adults call a character-builder. Translation: Few adults would want to do it.

But a couple of weeks ago, Trimaine showed how much character he already has. Translation: lots.

Trimaine loads grocery bags outside a Giant Food store at the Westbard Shopping Center in Bethesda. He's 16 years old. He lives in Washington. He has worked at the Giant three days a week for about six months.

If you've been to a Giant lately, you know that grocery carts are stacked in a long, wavy row outside the front door. When you arrive, you take one. When you leave, you replace your cart in the stack. Carts are never allowed into the parking lot unless someone has very special circumstances.

Part of the reason is that, after carts are unloaded, they can develop minds of their own and start rolling. I speak from bitter experience when I say that it's no fun to be whacked in the knee by a cart that has just covered 50 yards and is still picking up speed.

Anyway, the world being the way the world is, a shopper came out of the Westbard Giant the other day and blithely decided to break the rules. She wasn't disabled. She gave no sign of having just had surgery. She was just one of those selfish so-and-sos whose time is worth more than yours or mine.

The woman pushed her cart through the swinging gate that accommodates wheelchairs. She rolled across the lot, loaded her car and drove away.

Of course, she left the cart sitting there (What? You think she should have pushed it back to the wavy row? Heavens! Her ice cream might have melted!) It didn't take long for it to roll, roll, roll--and smash into a car belonging to a Levey reader. The damage: a long scratch along one side of the car.

Trimaine saw it happen. The cart-napper drove off before he could talk to her. But he knew what to do.

For the next 20 minutes, he stood beside the injured car, waiting for its owner to finish shopping. When she did, Trimaine explained who and what had caused the scratch. He also supplied the license number of the getaway car. My reader said she has "never seen such an incredibly nice act by anyone."

I wish I could tell you that Madame Selfish was hauled before some tribunal, where she was flogged 43 times with a head of Giant lettuce and then forced to pay up. In fact, the repair bill was less than the $250 deductible on my reader's auto insurance policy, and she decided not to bother going after the culprit.

However, Trimaine Williams "earns my undying respect," the woman said.

Ron Edwards, manager of the Westbard Giant, called him "a real good kid" who is "very, very in tune with how to deal with customers."

I call him a character-builder--for all of us who'd like to think we'd have done the same thing but know we might not have.

My Nov. 17 column bore a rather saucy headline, if I do say so myself (and I can, since I wrote it). It read: "The Clucks Who Approach Kids on Metro."

The following letter arrived two days later. It proves that offending people is easy to do.

"Dear Bob Levey,

"When I read your column today, I was extremely disturbed by your use of 'cluck' . . .

"When I married my husband 30 years ago, I joined a long tradition of hardworking German descendants who have high ethical standards.

"Sincerely, Cynthia Cluck, Reston."

Webster has been offending people even longer than I have. One of the meanings he lists for "cluck" is "a stupid or naive person." So at least I didn't invent the usage, Cynthia.

Nevertheless, I'm very sorry, and I hope you'll extend those sorries to your family. My new policy: Replace any potentially radioactive word with "columnist" and see if the shoe pinches. If it does, try, try again.

CHILDREN'S HOSPITAL

These groups have made donations to our annual fund-raising campaign in recent days:

Arnold Baggins Foundation, New Canaan, Conn. ($2,500).

American Legion Auxiliary, Fairfax ($50).

Federal Reprographics Association, Northeast Washington ($250, with special thanks to Wilma M. Grant).

International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers, Northwest Washington ($838 via a bake sale and raffles, with special thanks to Deborah L. Teta).

The Ladies of the Elks of 1778, Riverdale ($500).

Rockville Senior Associates, Rockville ($25).

Dick Clough's Income Tax Service ($250).

The Shrine of St. Jude Leisure Club, Rockville ($50).

Marriott International Inc. ($2,500).

Network and Customer Operations employees, Winstar, Herndon ($305).

Thanks very much to all.

Our goal by Jan. 21: $650,000.

In hand as of Dec. 6: $86,757.42.

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.

BY VISA OR MASTERCARD:

Call Post-Haste at 202-334-9000 on a touch-tone phone. Then punch in K-I-D-S, or 5437, and follow instructions.