Definition of word constant

Fatal error: Uncaught exception 'Exception' with message 'Can't connect to the api: http://api.wordnik.com/v4/word.json/constant/definitions?sourceDictionaries=wiktionary response code: 429' in /home/eli8manajr/englishtohindi/wordnik/Swagger.php:116 Stack trace: #0 /home/eli8manajr/englishtohindi/wordnik/WordApi.php(178): APIClient->callAPI('/word.json/cons...', 'GET', Array, NULL, Array) #1 /home/eli8manajr/englishtohindi/index.php(204): WordApi->getDefinitions('constant', NULL, 'wiktionary', NULL) #2 {main} thrown in /home/eli8manajr/englishtohindi/wordnik/Swagger.php on line 116