There are many nouns in Klingon that are two or, less frequently, three syllables long, but are not complex nouns of the types we've discussed. These nouns were probably formed by combining simple nouns at some point in the past, but now one or more of the original nouns are no longer in use. Because of this, it is not possible (without extensive entomological research) to know what the individual parts of the noun mean.

For example, 'ejDo' means "starship." The syllable 'ej also appears in 'ejyo' ("Starfleet"). However, there are no known Klingon words 'ej, Do', or yo' that are related to starfleets, starships, shuttlecraft or any kind of space vehicle. It's likely that Do' was an Old Klingon word for "space vessel" (the modern word is Duj), but it is now only used in the noun 'ejDo'. Without further study, though, this remains just a theory.