marrow marrow /ˈmɛroʊ/

noun

1. () The fatty network of connective tissue that fills the cavities of bones  ( bone marrow , marrow )
   the fatty network of connective tissue that fills the cavities of bones
   
   
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
   
3. [British] Large elongated squash with creamy to deep green skins  ( marrow [British] , vegetable marrow )
   large elongated squash with creamy to deep green skins
   
   
4. Very tender and very nutritious tissue from marrowbones  ( bone marrow , marrow )
   very tender and very nutritious tissue from marrowbones
   
   
5. Any of various squash plants grown for their elongated fruit with smooth dark green skin and whitish flesh  ( marrow , marrow squash , vegetable marrow )
   any of various squash plants grown for their elongated fruit with smooth dark green skin and whitish flesh