[1] : The Collaborative International Dictionary of English v.0.48

gaoler \gaol"er\ j=al"~er, n.
   the keeper of a jail. same as jailer.
   1913 webster
see also:
jailer 

[2] : The Collaborative International Dictionary of English v.0.48

jailer \jail"er\, n. oe. jailer, gailer, of. geolier, f.
   ge^olier. see jail.
   the keeper of a jail or prison. written also jailor,
   gaoler.
see also:
jail jailor gaoler 

[3] : WordNet (r) 2.0

gaoler
     n : someone who guards prisoners syn: prison guard, jailer,
          jailor, screw, turnkey
see also:
prison guard jailer jailor screw turnkey 

[4] : Bouvier's Law Dictionary, Revised 6th Ed (1856)

gaoler. the keeper of a gaol or prison, one who has the legal custody of the 
place where prisoners are kept. 
     2. it is his duty to keep the prisoners in safe custody, and for this, 
purpose he may use all necessary force. 1 hale, p. c. 601. but any 
oppression of a prisoner under a pretended necessity will be punished; for 
the prisoner, whether he be a debtor or a criminal, is entitled to the 
protection of the laws from oppression. 

Gaoler >> G Words
Gaoler, definition of term: Gaoler
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