"Danny Boy" was intended as a message from a woman to a man, and Weatherly provided the alternative "Eily dear" for male singers in his 1918 authorised lyrics. However, the song is actually sung by men as much as, or possibly more than, women. The song has been interpreted by some listeners as a message from a parent to a son going off to war.
The song is widely considered an Irish anthem, although Weatherly was an Englishman. (from Wikipedia).