regular expression question

I have a question regarding regular expression with postgres.

I am unable to find any reference to match on word boundaries (\b in
perl).  If this functionality exists in postgres I am interested in
knowing how to use it, an example would probably suffice.

If it does not, which is what I suspect, I am interested in knowing how
others have dealt with this problem.  It seems silly/ineffecient to just
try all cases, i.e. field ~* (^term| term | term$), but I can't think of a
better way.

Thanks,

Parker.
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