Such words are rare but do exist.
For example, consider whatsoever or longshoreman, or if you prefer other forms of transportation, aircraftman or highwayman.
The first is listed as a pronoun, but that seems likely to count as a noun for this question.
There are also adjectives such as workmanlike, adverbs such as hereinafter, etc.
See also this EL&U questionthis EL&U question I found after writing this answer.