apt in WordNet English dictionary

1. being of striking appropriateness and pertinence
   "the successful copywriter is a master of apposite and evocative verbal images"; "an apt reply"
   apposite  apt  pertinent 
   
2. (usually followed by `to') naturally disposed toward
   "he is apt to ignore matters he considers unimportant"; "I am not minded to answer any questions"
   apt  disposed  given  minded  tending 
   
3. mentally quick and resourceful
   "an apt pupil"; "you are a clever man...you reason well and your wit is bold"-Bram Stoker
   apt  clever 
   
4. at risk of or subject to experiencing something usually unpleasant
   "he is apt to lose"; "she is liable to forget"
   apt  liable