last part of a poem; latter half of a verse
Refers to the second half of a traditional Japanese poem (especially the last 7-7 syllables of a tanka) or the latter part of a Bible verse. Often contrasted with 上の句 (かみのく).
There is a game where you hear the last part of a Hyakunin Isshu poem and guess the first part.
Compound of 下 (しも, 'lower') + の (possessive particle) + 句 (く, 'phrase, verse'). The reading しも is the native Japanese reading of 下, and 句 is read with its on'yomi く.