log

# Create an italian word and add a definition to it
>> w = Word.create(:word => 'cestino', :language => :it)
#<Word _id: 4d41abc38b8e6b3001000002, word: "cestino", language: :it, origin: nil, pronunciation: nil>
>> w.definitions.create :kind => :noun, :text => 'un posto dove buttare le cose'
#<Definition _id: 4d42a9238b8e6b5fa2000003, kind: :noun, text: "un posto dove buttare le cose">

# Add a translation (a word in another language) to the definition

>> w.definitions.first.translations.create(:word => 'recycling bin', :language => :en)
NoMethodError: undefined method `first' for #<Definition:0x10668c020>
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/attributes.rb:75:in `method_missing'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/builders/embedded/many.rb:21:in `build'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/accessors.rb:59:in `create_relation'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/accessors.rb:26:in `build'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/accessors.rb:149:in `definitions='
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/extensions/object/yoda.rb:22:in `send'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/extensions/object/yoda.rb:22:in `do_or_do_not'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/bindings/referenced/many.rb:46:in `bind_one'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/referenced/many.rb:273:in `append'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/many.rb:44:in `build'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/many.rb:43:in `tap'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/many.rb:43:in `build'
	from /Users/Le/.rvm/gems/ree-1.8.7-2010.01/gems/mongoid-2.0.0.rc.6/lib/mongoid/relations/referenced/many.rb:70:in `create'
	from (irb):39
	from :0
>> w.definitions.first.translations
[
    [0] #<Word _id: 4d42a9a48b8e6b5fa2000004, word: nil, language: nil, origin: nil, pronunciation: nil>
]

models.rb

class Word
  include Mongoid::Document
  
  field :word
  field :pronunciation
  
  field :language
  field :origin
  
  embeds_many :definitions
  
  accepts_nested_attributes_for :definition
end

class Definition
  include Mongoid::Document
  
  field :kind
  field :text
  
  embedded_in :word
    
  references_many :synonims,     :class_name => 'Word'
  references_many :translations, :class_name => 'Word'
end