imperative vs insistent

imperative

adj
  • Of, or relating to the imperative mood. 

  • Having semantics that incorporates mutable variables. 

  • Expressing a command; authoritatively or absolutely directive. 

  • Essential; crucial; extremely important. 

noun
  • A verb in imperative mood. 

  • The grammatical mood expressing an order (see jussive). In English, the imperative form of a verb is the same as that of the bare infinitive. 

  • An essential action, a must: something which is imperative. 

insistent

adj
  • Urgent in dwelling upon anything; persistent in urging or maintaining. 

  • Extorting attention or notice; coercively staring or prominent; vivid; intense. 

  • Standing on end: specifically said of the hind toe of a bird when its base is inserted so high on the shank that only its tip touches the ground: correlated with incumbent. 

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