Entry 1 sense Webster, 1913 centrolinead /(sĕn`trō̇*lĭn"ē̇*ăd)/ · cen·tro·lin·e·ad · IPA 01 n. An instrument for drawing lines through a point, or lines converging to a center. 1. An instrument for drawing lines through a point, or lines converging to a center.