[ku3 xin1] /painstaking effort/to take a lot of trouble/laborious at pains/
  [ku3 xin1] /sorgfältig (u.E.)/
  [ku3 xin1] /application fervente/
 [くしん] /(n,vs) pain/trouble/anxiety/diligence/hard work/(P)/EntL1244530X/
Visszatérés a(z) „苦心” laphoz.