hefsek means an interruption in the performance of a mitzvah, rendering it invalid. Lexicurio rates it Rare gem — a strength score of 82 out of 100.
Etymology
From Hebrew הפסק.
noun
- An interruption in the performance of a mitzvah, rendering it invalid.“In order not to introduce a hefsayk (interruption) in the Zemirot section, some Sephardic congrgations recite the hymn either before Barukh She'amar or after the repetition of the Amidah.”