eau / oe / oh / owe [o:]
eau – n. – from the French for water, used only in expressions, i.e. eau de cologne – cologne, eau de vie – brandy, water of life, eau de toilette – stronger than cologne but weaker than perfume
oe – n. – 1. a violent whirlwind off the Faroe Islands
oh – interj. & n. – expressing surprise, pain, entreaty, etc.; n. – zero (also O)
owe – v. intr. – 1. be under obligation to pay or repay; 2. render gratitude or honour to; 3. be indebted to a person or thing; 4. under obligation to fulfill