From WordNet (r) 2.0 (August 2003) [wn]:
puppy
n 1: young dog
2: an inexperienced young person [syn: pup]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Puppy \Pup"py\, n.; pl. Puppies. [F. poup['e]e doll, puppet.
See Puppet, and cf. Pup, n.]
1. (Zool.) The young of a canine animal, esp. of the common
dog; a whelp.
[1913 Webster]
2. A name of contemptuous reproach for a conceited and
impertinent person.
[1913 Webster]
I found my place taken by an ill-bred, awkward puppy
with a money bag under each arm. --Addison.
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From The Collaborative International Dictionary of English v.0.48 [gcide]:
Puppy \Pup"py\, v. i. [imp. & p. p. Puppied; p. pr. & vb. n.
Puppying.]
To bring forth whelps; to pup.
[1913 Webster]