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diff --git a/contrib_bots/lib/DefineBot/docs.md b/contrib_bots/lib/DefineBot/docs.md
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+# DefineBot
+
+* This is a bot that defines a word that the user inputs. Whenever the user
+inputs a message starting with '@define', the bot defines the word
+that follows.
+
+* The definitions are brought to the website using an API. The bot posts the
+definition of the word to the stream from which the user inputs the message.
+If the user inputs a word that does not exist or a word that is incorrect or
+is not in the dictionary, the definition is not displayed.
+
+* For example, if the user says "@define crash", all the meanings of crash
+appear, each in a separate line.
+
+![Correct Word](correct_word.png)
+
+* If the user enters a wrong word, like "@define cresh" or "@define crish",
+then an error message saying no definition is available is displayed.
+
+![Wrong Word](wrong_word.png)
+
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diff --git a/contrib_bots/lib/define_bot.py b/contrib_bots/lib/define_bot.py
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+++ b/contrib_bots/lib/define_bot.py
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+# See readme.md for instructions on running this code.
+import logging
+import json
+import requests
+import html2text
+
+class DefineHandler(object):
+    '''
+    This plugin define a word that the user inputs. It
+    looks for messages starting with '@define'.
+    '''
+
+    DEFINITION_API_URL = 'https://owlbot.info/api/v1/dictionary/{}?format=json'
+    REQUEST_ERROR_MESSAGE = 'Definition not available.'
+    EMPTY_WORD_REQUEST_ERROR_MESSAGE = 'Please enter a word to define.'
+    PHRASE_ERROR_MESSAGE = 'Definitions for phrases are not available.'
+
+    def usage(DefineHandler):
+        return '''
+            This plugin will allow users to define a word. Users should preface
+            messages with "@define".
+            '''
+
+    def triage_message(DefineHandler, message):
+        # return True if we want to (possibly) response to this message
+        original_content = message['content']
+        # This next line of code is defensive, as we
+        # never want to get into an infinite loop of posting follow
+        # ups for own follow ups!
+        is_define = original_content.startswith('@define')
+
+        return is_define
+
+    def _handle_definition(DefineHandler, original_content):
+        # Remove '@define' from the message and extract the rest of the message, the
+        # word to define.
+        split_content = original_content.split(' ')
+
+        # If there are more than one word (a phrase)
+        if len(split_content) > 2:
+            return DefineHandler.PHRASE_ERROR_MESSAGE
+
+        to_define = split_content[1].strip()
+        to_define_lower = to_define.lower()
+
+        # No word was entered.
+        if not to_define_lower:
+            return DefineHandler.EMPTY_WORD_REQUEST_ERROR_MESSAGE
+        else:
+            response = '**{}**:\n'.format(to_define)
+
+            try:
+                # Use OwlBot API to fetch definition.
+                api_result = requests.get(DefineHandler.DEFINITION_API_URL.format(to_define_lower))
+                # Convert API result from string to JSON format.
+                definitions = api_result.json()
+
+                # Could not fetch definitions for the given word.
+                if not definitions:
+                    response += DefineHandler.REQUEST_ERROR_MESSAGE
+                else: # Definitions available.
+                    # Show definitions line by line.
+                    for d in definitions:
+                        example = d['example'] if d['example'] else '*No example available.*'
+                        response += '\n' + '* (**{}**) {}\n  {}'.format(d['type'], d['defenition'], html2text.html2text(example))
+
+            except Exception as e:
+                response += DefineHandler.REQUEST_ERROR_MESSAGE
+                logging.exception(e)
+
+            return response
+
+    def handle_message(DefineHandler, message, client, state_handler):
+        original_content = message['content']
+
+        response = DefineHandler._handle_definition(original_content)
+
+        client.send_message(dict(
+            type='stream',
+            to=message['display_recipient'],
+            subject=message['sender_email'],
+            content=response
+        ))
+
+handler_class = DefineHandler