halfhearted vs offhand

halfhearted

adj
  • Lacking full energy, effort, commitment, or resolve. 

offhand

adj
  • Careless; without sufficient thought or consideration. 

  • Without planning or thinking ahead. 

  • Curt, abrupt, unfriendly. 

adv
  • Right away, immediately, without thinking about it. 

  • In an offhand (adjective) manner. 

How often have the words halfhearted and offhand occurred in a corpus of books? (source: Google Ngram Viewer )