Y-AXIS Meaning of Y-AXIS in English y-ax ‧ is /ˈwaɪ ˌæksəs/ BrE AmE noun [singular] technical the line marked with numbers that goes from top to bottom on a ↑ graph SYN vertical axis ⇨ x-axis Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012