…the rest is needed
(Honeori zon no kutabire mouke;
“Bone-breaking loss and a profit of weariness”)
Working hard without any reward. Bone-breaking labor with no fruits but exhaustion. A wasted effort or thankless task.
It turns out that this whole kotowaza is a noun phrase build of subsidiary noun phrases, most of them derived from verbs. We begin at the end with the verb 儲ける (moukeru), “to earn,” “to profit,” in conjunctive form and acting as a noun. This is preceded and modified by the verb 草臥れる (kutabireru), “to be exhausted,” “to wear out,” in conjunctive form and acting as a noun. Associative particle の (no) connects this noun phrase to the noun 損 (son), “loss,” “harm”; this is preceded and modified by a compound noun comprising the noun 骨 (hone, rhymes with Monet), “bone,” and the verb 折る (oru), “to fold,” “to break,” in conjunctive form and, you guessed it, acting as a noun. Backing up a bit, we see that one of the effects of being in a compound is that son is voiced as zon.
Note the (ironically twisted) rhetorical contrast between 損 and 儲け (loss and profit, or expenditure and return).
The kanji for 草臥れる are apparently derived from the ancient Chinese text Classic of Poetry (詩経, Japanese Shikyou), which at some point describes a tired person lying down (臥) on the grass (草). The Japanese phonetic root is from the same source as 朽ちる (kuchiru), “to rot (away).”
This phrase is the ほ entry of the Edo iroha karuta set. The latter half (草臥れ儲け) may also appear on its own as shorthand for the entire phrase.
(“Kodomo no toki, gakkou de no benkyou wa honeori zon no kutabire mouke da to omotteta kedo, toshokan de sugoshita heijitsu no yuugata wa gokuraku mitai na jikan deshita.”)
[“When I was a kid, I thought that studying at school was a colossal waste of effort, but the weekday evenings I spent at the library were like paradise.”]