el querellante, la querellante - plaintiff in a legal action...
  quimérico - fanciful, highly improbable,...
  el quinceañero, la quinceañera - specifically, a 15-year-old, or, more...
  el quinqui, la quinqui - petty thief, delinquent, hoodlum
  el queso - cheese
  el quilate - carat, karat
  quizás, quizá - maybe, perhaps
  quirúrgico - surgical
  el quiosco - kiosk, newspaper stand, bandstand
  la quintaesencia - the ultimate or most typical instance...
  el quebradero de cabeza - headache in the sense of someone or...
  quienquiera - whoever
  a quemarropa - at point-blank range, extremely close
  el quehacer - task, something that needs doing, to-do
  la querencia - place someone feels at home, a...
  quijotesco - quixotic, idealistic but impractical
  el quejica, la quejica - whiner, chronic complainer
  la quemadura - burn, scald
  las quimbambas - boondocks, boonies, somewhere in the...
  quincenalmente - every two weeks, twice a month,...