How to Describe a field in the table???

Hi,

Im porting my programs from mySQL to PG.
mySQL supports a query "DESCRIBE tablename fieldname" , that provides a

detailed
description of a specific table field.

Is there such an equivalent in PG?
"\d tablename" gives description for all the fields in the table,
however I need to find
out a description for a specific field only.

Regards,
Boulat