declare @ObjectName nvarchar(max)='objectName'
SELECT  o.[name] as object_name
                                                            , sm.[definition]
                                                    FROM sys.sql_modules AS sm
                                                    JOIN sys.objects AS o
                                                        ON sm.object_id = o.object_id
                                                    JOIN sys.schemas AS ss
                                                        ON o.schema_id = ss.schema_id
where o.name=@ObjectName