Lipid and Macromolecule

Lipid noun - An oily organic compound insoluble in water but soluble in organic solvents; essential structural component of living cells (along with proteins and carbohydrates).

Macromolecule and lipid are semantically related. In some cases you can use "Macromolecule" instead a noun "Lipid".

Macromolecule noun - Any very large complex molecule; found only in plants and animals.

Lipid and macromolecule are semantically related. Sometimes you can replace term "Lipid" with "Macromolecule", this nouns are similar.