Just to add even more evidence that my original example of a word with only one meaning was entirely incorrect:
"I really like the teacups."
That now has three potential meanings:
1) I really like the china crockery from which we drink tea.
2) I really like the small poodles.
3) I really like the circus ride where you sit in a giant teacup and it spins round and makes you dizzy.
I hope the OP can now see how context really is important.
- For Teachers