euphoric vs happy as a lark

euphoric

adj
  • Feeling great well-being or elation or intense happiness; characterized by euphoria 

  • Productive of euphoria, causing great joy 

noun
  • A drug that causes euphoria; a euphoriant. 

happy as a lark

adj
  • Very happy (sometimes with the extra connotations of being carefree or unaware of grimmer realities). 

How often have the words euphoric and happy as a lark occurred in a corpus of books? (source: Google Ngram Viewer )