ictus (n.)

rhythmical or metrical stress, 1752, from Latin ictus "a blow, stroke, thrust;" of voices "a beat, impulse, stress," from icere (past participle ictus) "to strike, hit," which is related to iacere "to throw" (from PIE root *ye- "to throw, impel"). Reckoned in Anglo-Saxon poetry; in Modern English it generally is identical to syllabic stress or accent.