" larkiness "

1: a natural disposition for playful behavior;

  * e.g., " ... within the confines of the private club, these hotshot lawyers display a larkiness that would do a frat boy proud "

•  Synonyms : 

•  coltishness,

•  espièglerie,

•  friskiness,

•  impishness,

•  mischief,

•  mischievousness,

•  playfulness,

•  prankishness,

•  sportfulness,

•  sportiveness,

•  tricksiness

•  Antonyms : 

•  earnestness,

•  soberness,

•  sobersidedness

1: given to good-natured joking or teasing;

  * e.g., " ... a larky group of youths enjoying a night out on the town "

•  Synonyms : 

•  antic,

•  coltish,

•  elfish,

•  fay,

•  frisky,

•  frolicsome,

•  playful,

•  rollicking,

•  sportful,

•  sportive

•  Antonyms : 

•  earnest,

•  serious-minded,

•  sober,

•  sobersided