| Word | Description |
| Margarine | A dairy product similar to butter but made from milks, milk products, oils, and other ingredients. |
| Marinara | A sauce of tomatoes, onions, garlic and spices. |
| Mastic | A thick paste that provides a permanent seal at duct joints and connections; sometimes used in conjunction with a fiberglass mesh tape |
| MEF | Modified Energy Factor; measures the energy used during the washing process as a whole, including washing machine energy, water heating energy, and dryer energy required for the removal of the remaining moisture in the wash load; the higher the MEF, the more efficient the clothes washer |
| midges | Whitish-yellow 1/12” maggots that feed on flower buds |
| Multi-vitamin | A multivitamin is any preparation containing more than a single vitamin. Tablets and injectable forms are available. In common usage, "multivitamin" refers to tablets that contain various vitamins usually along with dietary minerals and, occasionally, herbal extracts. |
| mycorrhiza | A mutually beneficial association of a fungus and the roots of a plant such as a conifer or an orchid, in which the plant's mineral absorption is enhanced and the fungus obtains nutrients |
