I don't quite understand what you mean.
I gave the 98 an ip address, does that mean it's defined?
Yes.
What does the word "defined" mean to you?
http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=defined&x=18&y=12
Main Entry: de·fine
Pronunciation: di-'fIn
Function: verb
Inflected Form(s): de·fined; de·fin·ing
Etymology: Middle English, from Middle French & Latin; Middle French
definer, from Latin definire, from de- + finire to limit, end, from
finis boundary, end
transitive senses
1 a : to determine or identify the essential qualities or meaning of
<whatever defines us as human> b : to discover and set forth the meaning
of (as a word) c : to create on a computer <define a window> <define a
procedure>
2 a : to fix or mark the limits of : DEMARCATE <rigidly defined property
lines> b : to make distinct, clear, or detailed especially in outline
<the issues aren't too well defined>
3 : CHARACTERIZE, DISTINGUISH <you define yourself by the choices you
make -- Denison Univ. Bull.>
intransitive senses : to make a definition
Steve