clam: [OE] Old English clam meant ‘something for tying up or fastening, fetter’; it can be traced back to a prehistoric Germanic base *klam-, which also produced clamp [14] and is related to climb. There is a gap in the word’s history in early Middle English times, but it reappears at the end of the 14th century in the sense ‘clamp’, and in the 16th century it was applied, originally in Scotland, to the mollusc which now bears the name, apparently on the grounds that its two shells close like the jaws of a clamp or vice. => clamp, climb
clam (n.)
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" (cognates: 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.
clam (v.)
"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.
例文
1. The barnacle and the clam are two examples of filter feeders.
フジツボとアサリ類は、捕食者を濾過した2つの例である。
2.It 'started off well，but he seemed to clam up towards the end.
最初はよかったが、最後は少し黙っていたようだ。
3.The movie star is a clam about her age.
この映画スターは彼女の年齢に対して口をつぐんでいる。
4.Everybody shuts up like a clam as soon as you mention it.