Kalmar "macrencephalic" ta ƙunshi sassa biyu: "macro" ma'ana babba, da "encephalic" ma'anar da ke da alaƙa da kwakwalwa. Don haka, ma'anar ƙamus na "macrencephalic" zai kasance "samun babban kwakwalwa ko kwakwalwa dangane da girman jiki ko wasu nau'in." Ana amfani da wannan kalma sau da yawa a ilmin halitta don kwatanta dabbobi ko jinsuna masu manyan kwakwalwa dangane da girman jikinsu ko kwatanta da sauran nau'in.