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Related to clam: clam up

close as a clam

Safe from harm. Likened to a clam closing its shell to protect itself. All of the doors and windows are locked. Don't worry, we'll be close as a clam in here.
See also: clam, close

happy as a clam at high tide

Very joyful and content. Clams are dug at low tide, so a clam at high tide would be able to remain uncaught. Look at your sister out there! She's happy as a clam at high tide now that she's back in the starting lineup again. I know I'll be happy as a clam at high tide once I get this stupid cast off my leg.
See also: clam, happy, high, tide

clam up

To suddenly stop talking or refuse to speak, typically due to a particular reason. The phrase refers to a clam closing its shell. Naturally, everyone clammed up as soon as the check came. Our usual informant clammed up when he realized there was a mole in the department.
See also: clam, up

clam up

to say nothing. (Closing one's mouth in the way that a clam closes up.) The minute they got him in for questioning, he clammed up. You'll clam up if you know what's good for you.
See also: clam, up

*happy as a clam (at high tide)

 and *happy as a clam (in butter sauce); *happy as a lark; *happy as can be
contented; very happy. (*Also: as ~.) I've been as happy as a clam since I moved to the country. I don't need much. Just somewhere to live, some work to do, and a TV to watch, and I'm happy as a clam at high tide. Matthew was happy as a lark throughout his whole vacation. Bob was happy as can be when he won the lottery.
See also: clam, happy

clam up

to refuse to talk or answer Every time I think he's going to tell me what's bothering him, he just clams up.
Etymology: based on the behavior of a clam (a sea creature), which quickly closes its shell when something touches it
See also: clam, up

(as) happy as a clam

very happy I am happy as a clam living all by myself in this little house by the sea.
Etymology: based on the full form of the phrase happy as a clam in mud at high tide (a clam that cannot be dug up and eaten, which therefore could be considered happy)
See also: clam, happy

be as happy as Larry/a sandboy

  (British & Australian) also be as happy as a clam (American)
to be very happy and to have no worries We married nine days after we met, and three years on we're happy as Larry. Since he's been at college he's as happy as a clam.
See also: happy, Larry, sandboy

shut up like a clam

to suddenly stop talking and to refuse to say any more
Usage notes: A clam is a fish with a shell which closes up very quickly if something attacks it.
When I asked him about his trip to Korea, he shut up like a clam.
See also: clam, like, shut, up

clam up

Refuse to talk or respond, as in Whenever she asks her teenager about his activities, he clams up. This term alludes to the tightly closed valves of a live clam. [Slang; early 1900s]
See also: clam, up

happy as the day is long

Also, happy as a lark; happy as a clam (at high tide). Extremely glad, delighted, very cheerful, as in He was happy as the day is long, or When she heard the news she was happy as a lark, or Once I got the test results I was happy as a clam at high tide. The first of these similes dates from the late 1700s. The second alludes to the lark's beautiful, seemingly very happy, song. The third, from the early 1800s, alludes to the fact that clams can only be dug at low tide and therefore are safe at high tide; it is often shortened to happy as a clam.
See also: happy, long

clam up

v. Slang
To refuse to talk or to stop talking suddenly: The politician clammed up when the reporters started to ask about the scandal.
See also: clam, up


1. n. a dollar. (Underworld.) You got a couple of clams I can bum for a little bottle?
2. n. a tight-lipped person. Suddenly, she became a clam and wouldn’t talk anymore.

clam up

in. to get quiet. (see also dummy up.) The minute they got him inside the cop-shop, he clammed up.
See also: clam, up
References in periodicals archive ?
Many people would be surprised to learn that clam production, or aquaculture, is an important part of Florida's sea food economy.
Considering reported ideal temperatures of 23-25[degrees]C for larval survival (Robinson & Breese 1984), earlier spawning may be advantageous for larval survival and major recruitment for Manila clam larvae (Xie & Burnell 1994).
Any food business that is offered or has gathered such razor clams should not use them in connection with their food business.
Many come in for a cold draft beer and freshly shucked clams and oysters on ice.
After spending time in the aquarium's quarantine area, the clams will go on display in the aquarium's tropical oceans area.
The southern giant clams, which can grow up to 60cm in length, were part of a large consignment which was intercepted and confiscated after they were illegally imported in to the country.
Scrub the clams, discarding any that stay open when tapped sharply.
Voegel explained that clams are bottom-dwelling filter feeders, obtaining nutrients by filtering the water around them.
Each clam was opened with the use of a scalpel, and the viscera removed from the valves.
The wind-protected nature and shallowness of Vembanad Lake permits clam harvesting and finfishing throughout the year.
However, the nutrient-rich waters of coastal Alaska are still too cold for bivalves to reproduce sustainably, so oyster and clam farmers purchase "spat" (infant bivalves) that are then raised in nursery operations.
Clams are really a wonderful part of Italian cuisine, because they can be used in so many different ways," says head chef Bruno Barbieri, who always has clam dishes on the menu at his Michelin two-star Ristorante Arquade at Verona's Villa del Quar Hotel.
However, we do have to give the market some claps of the clam shells for its creativity - an addition of celery and red pepper was the only deviation from the standard ingredients on our quest.
Clam Gardens: Aboriginal Mariculture on Canada's West Coast Judith Williams New Star Books 112 pages, softcover ISBN 9781554200238