n. 孪生, 成对

[医] 对裂, 成对; 双生, 双胎生成

[ adj ]
producing two offspring at a time
<adj.all>

Twin \Twin\, v. i. [imp. & p. p. {Twinned}; p. pr. & vb. n.
{Twinning}.]
1. To bring forth twins. --Tusser.

2. To be born at the same birth. --Shak.


Twinning \Twin"ning\, n. (Crystallog.)
The assemblage of two or more crystals, or parts of crystals,
in reversed position with reference to each other in
accordance with some definite law; also, rarely, in
artificial twinning (accomplished for example by pressure),
the process by which this reversal is brought about.

{Polysynthetic twinning}, repeated twinning of crystal
lamell[ae], as that of the triclinic feldspars.

{Repeated twinning}, twinning of more than two crystals, or
parts of crystals.

{Twinning axis}, {Twinning plane}. See the Note under {Twin},
n.