Is “haphazard” a unique word?

Solution 1:

No. Trying to find other examples is an uphill battle, though.

In greater detail: Words that came from Greek and have a 'ph' in a single morpheme tend to use the /f/ pronunciation (except some cases like "Stephen" where it's /v/ — voiced instead of unvoiced). However, words that were formed by combining separate morphemes (such as uphill, loophole, haphazard, etc) have a 'ph' that belongs to two morphemes and does not represent an /f/ sound.