this is postgresql question..how do i drop unique constraint on a column?

content in content table has unique constraint..(although i can't see it
with \d content)

how can i drop that constraint?
thank you

mydb=# \d content
           Table "content"
    Attribute    |  Type   | Modifier
-----------------+---------+----------
 content_id      | integer | not null
 content         | text    | not null
 title           | text    |
 description     | text    |
 content_type_id | integer | not null
Indices: content_content_key,
         content_pkey

mydb=#