any of various bivalve mollusks, especially certain edible species.Compare quahog, soft-shell clam.
Informal. a secretive or silent person.
Slang. a dollar or the sum of a dollar: I only made 60 clams a week.

verb (used without object), clammed, clam·ming.

to gather or dig clams.

Verb Phrases

clam up, Slang. to refuse to talk or reply; refrain from talking or divulging information: The teacher asked who had thrown the eraser, but the class clammed up.

Origin of clam

1585–95; short for clam-shell, i.e., bivalve with a shell that clamps. See clam2, shell
Related formsclam·like, adjectiveclam·mer, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for clammed

Contemporary Examples of clammed

  • When Peruvian authorities refused to send him back to Aruba, he clammed up.

    The Daily Beast logo
    Van der Sloot's Lawyer Trouble

    Barbie Latza Nadeau, Dan Collyns

    June 14, 2010

  • Months later, when I challenged Colonel Boyatt on this highly counterproductive order to his troops, he clammed up on me.

    The Daily Beast logo
    Bill Clinton's Shameful Haiti Legacy

    Bob Shacochis

    January 19, 2010

Historical Examples of clammed

  • Kellner had clammed up, and when the now suspicious editor had tried to check Colquhoun's tale personally, Colquhoun had vanished.

    Cue for Quiet

    Thomas L. Sherred

  • But he clammed up about that, hoping to keep it a secret until he could go back and claim it.

    The Space Pioneers

    Carey Rockwell

  • The crack above the door should not be clammed until the muffle begins to get warm.

  • Clammed means starvation; that is, care killed the cat; for want of food the entrails get "clammed."

British Dictionary definitions for clammed




any of various burrowing bivalve molluscs of the genera Mya, Venus, etc. Many species, such as the quahog and soft-shell clam, are edible and Tridacna gigas is the largest known bivalve, nearly 1.5 metres long
the edible flesh of such a mollusc
informal a reticent person

verb clams, clamming or clammed

(intr) mainly US to gather clams
See also clam up

Word Origin for clam

C16: from earlier clamshell, that is, shell that clamps; related to Old English clamm fetter, Old High German klamma constriction; see clamp 1



verb clams, clamming or clammed

a variant of clem
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for clammed



bivalve mollusk, c.1500, in clam-shell, originally Scottish, apparently a particular use from Middle English clam "pincers, vice, clamp" (late 14c.), from Old English clamm "bond, fetter, grip, grasp," from Proto-Germanic *klam- "to press or squeeze together" (cf. Old High German klamma "cramp, fetter, constriction," German Klamm "a constriction"). If this is right then the original reference is to the shell. Clam-chowder attested from 1822. To be happy as a clam is from 1833, but the earliest uses do not elaborate on the notion behind it, unless it be self-containment.



"to dig for clams," 1630s, American English, from clam (n.). Clam up "be quiet" is 1916, American English, but clam was used in this sense as an interjection mid-14c.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with clammed


In addition to the idiom beginning with clam

  • clam up

also see:

  • happy as the day is long (as a clam)
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.