essential.1a.aEisintiúil. bRiachtanach. Essential foodstuffs, ábhair riachtanacha bia. It is essential that a doctor should be called, ní foláir fios a chur ar dhochtúir. Prudence is essential, caithfear bheith críonna. cSee OIL12s.Riachtanas m, buntréith f. ►essentially, adv.Go bunúsach.