辅助发动机
移动式蒸气机

Donkey \Don"key\ (d[o^][ng]"k[y^]), n.; pl. {Donkeys}
(d[o^][ng]"k[i^]z). [Prob. dun, in allusion to the color of
the animal + a dim. termination.]
1. An ass; or (less frequently) a mule.

2. A stupid or obstinate fellow; an ass.

{Donkey engine}, a small auxiliary engine not used for
propelling, but for pumping water into the boilers,
raising heavy weights, and like purposes.

{Donkey pump}, a steam pump for feeding boilers,
extinguishing fire, etc.; -- usually an auxiliary.

{Donkey's eye} (Bot.), the large round seed of the {Mucuna
pruriens}, a tropical leguminous plant.

doctor \doc"tor\, n. [OF. doctur, L. doctor, teacher, fr. docere
to teach. See {Docile}.]
1. A teacher; one skilled in a profession, or branch of
knowledge; a learned man. [Obs.]

One of the doctors of Italy, Nicholas Macciavel. --
Bacon.

2. An academical title, originally meaning a man so well
versed in his department as to be qualified to teach it.
Hence: One who has taken the highest degree conferred by a
university or college, or has received a diploma of the
highest degree; as, a doctor of divinity, of law, of
medicine, of music, or of philosophy. Such diplomas may
confer an honorary title only.

3. One duly licensed to practice medicine; a member of the
medical profession; a physician.

By medicine life may be prolonged, yet death
Will seize the doctor too. -- Shak.

4. Any mechanical contrivance intended to remedy a difficulty
or serve some purpose in an exigency; as, the doctor of a
calico-printing machine, which is a knife to remove
superfluous coloring matter; the doctor, or auxiliary
engine, called also {donkey engine}.

5. (Zo["o]l.) The friar skate. [Prov. Eng.]

{Doctors' Commons}. See under {Commons}.

{Doctor's stuff}, physic, medicine. --G. Eliot.

{Doctor fish} (Zo["o]l.), any fish of the genus {Acanthurus};
the surgeon fish; -- so called from a sharp lancetlike
spine on each side of the tail. Also called {barber fish}.
See {Surgeon fish}.