pith pith /ˈpɪθ/

noun

1. () Soft spongelike central cylinder of the stems of most flowering plants  ( pith )
   soft spongelike central cylinder of the stems of most flowering plants
    The white pith was carefully removed before juicing the oranges
   The white pith was carefully removed before juicing the oranges
   
2. The choicest or most essential or most vital part of some idea or experience  ( centre [Canadian, British] , gist , heart and soul , inwardness , kernel , marrow , meat , nitty-gritty , nub , center [American] , core , essence , heart , pith , substance , sum )
   the choicest or most essential or most vital part of some idea or experience
    The gist of the prosecutor's argument
   the gist of the prosecutor's argument
    The heart and soul of the Republican Party
   the heart and soul of the Republican Party
    The nub of the story
   the nub of the story
   

verb

1. Remove the pith from (a plant)  ( pith )
   remove the pith from (a plant)