亘る[wataru] to cross over
幾年にも亘る[ikunennimowataru] extending over a number of years
亘古[kouko] for ever
連亘[renkou] extending in a row

に亘って[niwatatte] throughout
長きに亘る[nagakiniwataru] long (used with period of time)
に亘り[niwatari] throughout

鳥渡[choto] just a minute
応急渡河[oukyuutoka] hasty crossing
下げ渡す[sagewatasu] to make a (government) grant
仮渡し[kariwatashi] temporary approximate payment
過渡[kato] crossing

過渡期[katoki] transition period
過渡的[katoteki] transitional
橋渡し[hashiwatashi] bridge building
響き渡る[hibikiwataru] to resound
見渡す[miwatasu] to look out over