" offhandedly "

1: as in casually, carelessly;

•  Synonyms : 

•  arbitrarily,

•  capriciously,

•  carelessly,

•  casually,

•  indiscriminately,

•  informally,

•  offhand,

•  promiscuously,

•  whimsically,

•  aimlessly,

•  anyhow,

•  anyway,

•  anywise,

•  desultorily,

•  erratically,

•  haphazard,

•  haphazardly,

•  helter-skelter,

•  hit or miss,

•  irregularly,

•  randomly,

•  willy-nilly,

•  accidentally,

•  fortuitously,

•  inadvertently,

•  unconsciously,

•  unintentionally,

•  unwittingly,

•  disconnectedly,

•  disjointedly,

•  fitfully,

•  intermittently,

•  spottily,

•  unpredictably,

•  higgledy-piggledy,

•  topsy-turvy

•  Antonyms : 

•  methodically,

•  systematically,

•  carefully,

•  formally,

•  gingerly,

•  meticulously,

•  orderly,

•  punctiliously,

•  deliberately,

•  intentionally,

•  purposefully,

•  purposely

1: made or done without previous thought or preparation;

  * e.g., " ... a quick, offhanded suggestion that was actually much better than any of the prepared proposals "

•  Synonyms : 

•  ad hoc,

•  ad-lib,

•  down and dirty,

•  extemporaneous,

•  extemporary,

•  extempore,

•  impromptu,

•  improvisational,

•  improvised,

•  off-the-cuff,

•  offhand,

•  snap,

•  spur-of-the-moment,

•  unconsidered,

•  unplanned,

•  unpremeditated,

•  unprepared,

•  unrehearsed,

•  unstudied

•  Antonyms : 

•  considered,

•  planned,

•  premeditated,

•  premeditative,

•  prepared,

•  rehearsed