ictus (IK-tuhs) - n., (pros./mus.) a metrical or rhythmical stress as contrasted on the one hand with an unstressed syllable/note and on the other with the stress accent on words; (pros.) a mark indicating same; (physio.) the pulse; (physio.) a sudden attack, blow, stroke, or seizure.
Borrowed around 1700 from Latin, from icere, to strike, plus -tus suffix of verbal action.
By way of noting that posting is likely to be sporadic next week due to offline obligations. Things should clear up again after that, though.