A word that is pronounced the same as another word but differs in meaning and/or spelling is a homophone. They abound in the English language: phase and faze, maid and made and straight and strait – it’s an inexhaustible list.
I always thought the grand champion among homophones is air, which has five other words pronounced likewise: are (as in a unit of land measurement), e’er (poetic contraction of ‘ever’), ere, err, and heir. Literary heroine Jane Eyre would make six, but a proper noun is obviously unallowable.
There is a group of true ‘septuplets’: raise, rays, rase, raze, rehs, réis, res (rase is a verb meaning ‘to erase’, rehs is the plural of reh, a mixture of sodium salts found as an efflorescence in India, réis is the plural of real, a currency unit of Portugal and Brazil, res is the plural of re, the second note of the do-remi musical scale).
In recreational linguistics (a fancy term for word play) an oronym (also called a continunym or a slice-onym) is a pair of phrases that are homophonic. When pronounced without a pause between words, phrases differing in meaning and spelling may share a similar pronunciation. An example is ‘ice cream’ and ‘I scream’, but more hilarious examples exist. For instance, here’s a definition of ‘washable’: “what a cowboy does very, very carefully” (wash a bull). In his short story collection Uncle Dynamite, PG Wodehouse creates one:
Lord Ickenham: (of his wife) “She is taking a trip in the West Indies”. Bill: “Jamaica?” Lord I: “No, she went of her own free will”.
Finally, a lesson constructed as a poem by someone who calls himself Homer Simpson, on the pitfalls of using the wrong word simply because it sounds right, and so escapes your spellcheck: Eye have a spelling chequer, It came with my Pea Sea. It plane lee marks four my revue Miss Steaks I can knot sea. Eye strike the quays and type a whirred And weight four it two say Weather eye am write oar wrong It tells me straight a weigh. Eye ran this poem threw it, Your shore real glad two no. Its vary polished in its weigh. My chequer tolled me sew.