The words mote, moat sound the same but have different meanings and spellings. Why do mote, moat sound the same even though they are completely different words?
The answer is simple: mote, moat are homophones of the English language.
A deep wide ditch, usually filled with water, typically surrounding a fortified medieval town, fortress, or castle as a protection against assault.
A ditch similar to one surrounding a fortification: A moat separates the animals in the zoo from the spectators.
To surround with or as if with a moat.
A very small particle; a speck: "Dust motes hung in a slant of sunlight” ( Anne Tyler).
Archaic May; might.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.