later on vs proximate

later on

adv
  • At some time in the future; subsequently; later. 

proximate

noun
  • A grammatical marker that distinguishes a relatively salient referent in a given context from a relatively non-salient (obviative) one. 

adj
  • Close or closest; adjacent. 

  • Immediately preceding or following in a chain of causation. 

  • About to take place; impending. 

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