n. 双胞胎中一人, 一对非常相像的人(或物)中的一个

a. 双胞胎的, 成对的, 孪生的

vi. 生双胞胎, 成对

vt. 怀(双胞胎), 使成对

[化] 孪晶

[医] 双胎, 双生儿

Twin \Twin\, v. i.
To depart from a place or thing. [Obs.] ``Ere that we farther
twin.'' --Chaucer.


Twin \Twin\, a. [OE. twin double, AS. getwinne two and two, pl.,
twins; akin to D. tweeling a twin, G. zwilling, OHG.
zwiniling, Icel. tvennr, tvinnr, two and two, twin, and to
AS. twi- two. See {Twice}, {Two}.]
1. Being one of two born at a birth; as, a twin brother or
sister.

2. Being one of a pair much resembling one another; standing
the relation of a twin to something else; -- often
followed by to or with. --Shak.

3. (Bot.) Double; consisting of two similar and corresponding
parts.

4. (Crystallog.) Composed of parts united according to some
definite law of twinning. See {Twin}, n., 4.

{Twin boat}, or {Twin ship} (Naut.), a vessel whose deck and
upper works rest on two parallel hulls.

{Twin crystal}. See {Twin}, n., 4.

{Twin flower} (Bot.), a delicate evergreen plant ({Linn[ae]a
borealis}) of northern climates, which has pretty,
fragrant, pendulous flowers borne in pairs on a slender
stalk.

{Twin-screw steamer}, a steam vessel propelled by two screws,
one on either side of the plane of the keel.


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.


Twin \Twin\, n.
1. One of two produced at a birth, especially by an animal
that ordinarily brings forth but one at a birth; -- used
chiefly in the plural, and applied to the young of beasts
as well as to human young.

2. pl. (Astron.) A sign and constellation of the zodiac;
Gemini. See {Gemini}.

3. A person or thing that closely resembles another.

4. (Crystallog.) A compound crystal composed of two or more
crystals, or parts of crystals, in reversed position with
reference to each other.

Note: The relative position of the parts of a twin may be
explained by supposing one part to be revolved 180[deg]
about a certain axis (called the twinning axis), this
axis being normal to a plane (called the twinning
plane) which is usually one of the fundamental planes
of the crystal. This revolution brings the two parts
into parallel position, or vice versa. A contact twin
is one in which the parts are united by a plane
surface, called the composition face, which is usually
the same as the twinning plane. A penetration twin is
one in which the parts interpenetrate each other, often
very irregularly. Twins are also called, according to
form, cruciform, geniculated, etc.


Twin \Twin\, v. t.
1. To cause to be twins, or like twins in any way. --Shak.

Still we moved
Together, twinned, as horse's ear and eye.
--Tennyson.

2. To separate into two parts; to part; to divide; hence, to
remove; also, to strip; to rob. [Obs.]

The life out of her body for to twin. --Chaucer.