Definition: each of two or more words having the same pronunciation but different meanings, origins, or spelling.
A few examples:
ate - eight
be - bee
mail - male
weight - wait
And one you'll see all over the Internet:
There ... Their ... They're
|There . . . . . . . in or at that place|
They're . . . contraction of "they are"
Do you have any words that trip you up?