Cite this: eDIL s.v. pharó or

ex (AN haro) a war-cry used by the Irish in the later Middle Ages: adeir Stanihurst an tan bhíd Éireannaigh ag comhrac . . . go n-abraid mar chomhairc do ghuth árd `Pharo, Pharo', Keat. i 42.73 . By Keating derived from ` faire ó' look out, oh! A survival of the Norman war-cry haro, still in use in Elizabethan literature (harow, harrow).