focal point in WordNet English dictionary

1. the concentration of attention or energy on something
   "the focus of activity shifted to molecular biology"; "he had no direction in his life"
   focus  focusing  focussing  focal point  direction  centering 
   
2. a point of convergence of light (or other radiation) or a point from which it diverges
   focus  focal point 
   
3. a central point or locus of an infection in an organism
   "the focus of infection"
   focus  focal point  nidus 
   

focal point in English Wiktionary