1635. What character can be added to both of these characters to give other characters? 敬_ -> _秀

Answer:

敬  KEI, uyama(u) - respect, revere

秀  SHUU, hii(deru) - excel, surpass

Add 言:敬+言 言+秀 

言   GEN, GON, i(u), koto - say, speech

警  KEI - admonish, warn

誘  YUU, saso(u) - invite, induce, lure, entice