approximation in WordNet English dictionary

1. the act of bringing near or bringing together especially the cut edges of tissue
   approximation  bringing close together 
   
2. the quality of coming near to identity (especially close in quantity)
   approximation 
   
3. an approximate calculation of quantity or degree or worth
   "an estimate of what it would cost"; "a rough idea how long it would take"
   estimate  estimation  approximation  idea 
   
4. an imprecise or incomplete account
   "newspapers gave only an approximation of the actual events"
   approximation