clamshell

From clam +‎ shell.

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clamshell (plural clamshells)

1. The shell of a clam.
2. Any object that, in (literal or figurative) resemblance to the shell of a clam, has a hinge on one edge and two surfaces that close together.
   • 1988 October 11, PC Mag, volume 7, number 17, page 93:

     You'll find a mix among clamshell laptops for strong laps, lunchboxes, and sewing-machine configurations; the latter two designs typically have detachable keyboards.

   1. A dredging bucket with hinges like the shell of a clam.
      • 2023 March 8, Chris Howe, “Building the platform for Old Oak Common's platforms”, in RAIL, number 978, page 60:

        The wall has been constructed one panel at a time by a machine which uses a clamshell bucket to excavate straight down to a depth of 30 metres. Specialised long-reach excavators with a clamshell grab then reach though the openings to lift the spoil to the surface, which is then deposited in articulated dump trucks (ADTs).

   2. In food service, the closing box (usually styrofoam but sometimes cardboard) given to consumers with takeout food.
   4. (obsolete, US, slang) mouth

      Shut your clam-shell!

      • 1858, Harper's Weekly‎:

        He was quickly silenced, however, by a burly individual, who "reckoned that it mout be jist as well for the stranger to keep his clam-shell shut."

      • 1870, Henry Perry Leland, The Grey-bay Mare, and Other Humorous American Sketches‎:

        "Shut your clamshell, Toby," grumbled the Baron.

3. (often attributive) Any object with some other resemblance to either one or both halves of the shell of a clam.
   1. (music) An amphitheater, especially an outdoor amphitheater; the semi-circular acoustic backdrop behind and above the performers.

      Synonym: bandshell

• clamshell phone

clamshell (third-person singular simple present clamshells, present participle clamshelling, simple past and past participle clamshelled)

1. (manufacturing) To deform a die in a shape resembling the shell of a clam, as a result of uneven extrusion pressure.
   • 2000, Charles A. Harper, Modern Plastics Handbook, pages 5–64:

     Although it produces a nonuniform pressure drop across the die and thus causes nonuniform flow through the die lip, the distribution of the melt does not produce die distortion of clamshelling.

   • 2012, M. J. Stevens, J. A. Covas, Extruder Principles and Operation, page 108:

     However, this solution is more susceptible to clamshelling, as the land length is particularly large at the centre.

2. To dig out by means of a clamshell (dredging bucket).
   • 1916, United States Congressional Serial Set, volume 6978, page 66:

     The additional handling that it would get by the canal would be: One dumping from the pockets into the canal barge, one clamshelling out of the canal barge, and one dumping onto the dock.

   • 1964, The American City - Volume 79, page 84:

     First the contractor clamshelled the silty material into two parallel dikes which are 200 feet apart.

   • 1976, Russell E. Train, Andrew W. Briedenbach, Ernst P. Hall, Edward L. Dulaney, Patricia e. WIlliams, John G. WIlliams, Development Document for Interim Final Effluent Limitations Guidlines And Proposed New Source Performance Standards for the Forming, Finishing and Specialty Steel Segments of the Iron and Steel Manufacturing Point Source Category, page 577:

     The sludge will be clamshelled and landfilled, or recycled to melting operations.

   • 1979, United States. Environmental Protection Agency. Effluent Guidelines Division, Draft Development Document for the Iron and Steel Manufacturing Point Source Category, page 102:

     Sludges produced at C must be periodically clamshelled out & transferred to controlled landfill.

   • 1993, Hsieh Wen Shen, S. T. Su, Feng Wen, Hydraulic Engineering '93, page 1196:

     Denser, more consolidated materials discharged at the disposal site, excavated by mechanical means (ie., clamshelled) descends more rapidly to the bottom and deposits at a density near to the in situ density at the dredging site (SAIC, 1987a/b).

3. To compress or flatten underwater debris so as to avoid blocking a channel.
   • 1972 March, Willard Beiley, “Underwater Brigade”, in Cincinnati Magazine, volume 5, number 6, page 49:

     In the past, when a boat sank and was judged unfit for salvage, the Coast Guard 'clamshelled' it. That is, they broke it up in order to flatten it as much as possible so it wouldn't obstruct river traffic.

4. (ambitransitive) To open or close by means of a hinge, similar to the way a clamshell opens and closes.
   • 1994 May-June, John Bastin, “ClamShelled”, in Mech, volume 3, number 94, page 14:

     To avoid getting clamshelled, first check the seat pins, then climb in before you pin the canopy.

   • 2012, Chris Bunch, Allan Cole, Juggernaut:

     Sixty-three of the transports grounded in a ring some 400 kilometers outside Cavite City, and their sides clamshelled and Tahn assault troops stormed out.

   • 2013, Martyn Jones, Falling Through the Stars:

     Richard replied bluntly as the safety harness automatically clamshelled comfortably around his hips and shoulders.

   • 2015, Kevin Lee Swaim, The Chimera Strain:

     He popped the release on the VISOR's helmet and it clamshelled open.

   • 2015, Wayne A. Pearson, White Shoulders:

     He clamshelled his phone.

   • 2017, David Drake, Lt. Leary, Commanding:

     This time, as soon as the hatches serving the water-level stern hold had clamshelled wide enough open, the twelve-place aircar assigned to heavy cruisers as a utility vehicle—the Princess Cecile had a jeep that could carry four if they were good friends —roared out.

   • 2018, Giampiero Campanelli, The Art of Hernia Surgery: A Step-by-Step Guide, page 429:

     If it is folded or clamshelled, this mesh should be removed if feasible to allow for placement of new mesh.

   • 2021, Ward Larsen, Assassin's Dawn:

     It lay on the writing desk, a laptop computer clamshelled shut.

• clamshell on Wikipedia.Wikipedia