The Collaborative International Dictionary of English v.0.48:
Fogy \Fo"gy\, n.; pl. Fogies.
1. A dull old fellow; a person behind the times,
over-conservative, or slow; -- usually preceded by old; an
old fogy. [Written also fogie and fogey.] [Colloq.]
[1913 Webster]
Notorious old bore; regular old fogy. --Thackeray.
[1913 Webster]
Note: The word is said to be connected with the German vogt,
a guard or protector. By others it is regarded as a
diminutive of folk (cf. D. volkje). It is defined by
Jamieson, in his Scottish Dictionary, as "an invalid or
garrison soldier," and is applied to the old soldiers
of the Royal Hospital at Dublin, which is called the
Fogies' Hospital. In the fixed habits of such persons
we see the origin of the present use of the term. --Sir
F. Head.
[1913 Webster]
2. (Mil.) In the United States service, extra pay granted to
officers for length of service. [Colloq.]
[Webster 1913 Suppl.]