く 苦の意味

《苦痛》(a) pain; suffering; 《困苦》hardship(s); (a) difficulty; 《心配》anxiety; worry; cares.
??になる　be anxious [worry] ((about)); 《事が主語》weigh on one's mind.
??にする　worry ((about, over)).
??にしない　take it easy.
??もなく　easily; with ease.
?は楽の種　No pain(s), no gain(s).