While there aren't many words ending in "ful" that aren't suffixes, here are a few possibilities:
* Ful: This is a word in itself, meaning "full" in Old English and occasionally still used today.
* Ful, as in "ful of" - sometimes found in older texts as a way of writing "full of."
It's important to note that these are very uncommon uses, and "ful" is overwhelmingly used as a suffix.
If you're looking for words that end in "ful" and are not suffixes, you're likely to find yourself in the realm of poetry or archaic language!