definition of
marrow

[1] #1 marrow n. [bone marrow] the fatty network of connective tissue that fills the cavities of bones. wn

[2] #2 marrow n. [marrow squash, vegetable marrow] any of various squash plants grown for their elongated fruit with smooth dark green skin and whitish flesh. wn

[3] #3 marrow n. [bone marrow] very tender and very nutritious tissue from marrowbones. wn

[4] #4 marrow n. [vegetable marrow] large elongated squash with creamy to deep green skins. wn

[5] #5 marrow n. [kernel, substance, core, center, centre, essence, gist, heart, heart and soul, inwardness, meat, nub, pith, sum, nitty-gritty] the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story". wn