Merriam-Webster Collegiate Dictionary - henry

 I. biographical name name of 8 kings of England: I 1068-1135 (reigned 1100-35); II 1133-1189 (reigned 1154-89); III 1207-1272 (reigned 1216-72); IV 1366-1413 (reigned 1399-1413); V 1387-1422 (reigned 1413-22); VI 1421-1471 (reigned 1422-61 & 1470-71); VII 1457-1509 (reigned 1485-1509); VIII 1491-1547 (reigned 1509-47)  II. biographical name name of 4 kings of France: I circa 1008-1060 (reigned 1031-60); II 1519-1559 (reigned 1547-59); III 1551-1589 (reigned 1574-89); IV (~ III of Navarre) 1553-1610 (reigned 1589-1610)  III. biographical name  1394-1460 the Navigator Portuguese prince  IV. biographical name Joseph 1797-1878 American physicist  V. biographical name O. — see William Sydney porter  VI. biographical name Patrick 1736-1799 American statesman & orator HENRY  noun  (plural ~s or henries)  Etymology: Joseph Henry  Date: circa 1890 the practical meter-kilogram-second unit of inductance equal to the self-inductance of a circuit or the mutual inductance of two circuits in which the variation of one ampere per second results in an induced electromotive force of one volt