skull /skʌl/
noun [countable][
Date: 1200-1300;
Origin: From a Scandinavian language]
1. the bones of a person’s or animal’s head
2. somebody can’t get it into their (thick) skull spoken someone is unable to understand something very simple:
He can’t seem to get it into his skull that I’m just not interested in him. [TahlilGaran] Dictionary of Contemporary English ▲