唯恐天下不乱

to wish for the whole world to be in chaos (idiom)

only / alone / -ism (in Chinese, a prefix, often combined with a suffix such as 主義|主义[zhu3 yi4] or 論|论[lun4], e.g. 唯理論|唯理论[wei2 li3 lun4], rationalism)

yes

for fear that / lest / also written 惟恐

afraid / frightened / to fear

day / sky / heaven

land under heaven / the whole world / the whole of China / realm / rule

down / downwards / below / lower / later / next (week etc) / second (of two parts) / to decline / to go down / to arrive at (a decision, conclusion etc) / measure word to show the frequency of an action

no; not so / (bound form) not; un-

in confusion or disorder / in a confused state of mind / disorder / upheaval / riot / illicit sexual relations / to throw into disorder / to mix up / indiscriminate / random / arbitrary