Compound noun

As described The Klingon Dictionary, a compound noun is a combination of two nouns creating one single new noun. A compound noun is treated as a single, indivisible unit with regard to suffixes. Multiple nouns can be merged together to become compound nouns, but it may also happen that we get a new noun that includes what appears to be an adjective or a verb as part of that noun. It just does not happen very often.

Examples

puqloD	son	puq child + loD man
jolpa'	transporter room	jol transport + pa' room

Creating compounds

Although it may be attractive to create compound words, this should be avoided. The rules that govern formation of compound nouns are not well-understood, and speakers should use the noun-noun construction when creating new noun concepts.

By convention, Klingonists don't combine words. Creating new noun combinations and presenting them as compound nouns is one of those moderately controversial practices that some accept more than others. Basically, if it comes from Okrand, it's okay. If it comes from someone else, then some people will accept it while others will reject it, and there is an odd kind of informal, intuitive sense that drives certain non-Okrand complex nouns to become more widely acceptable than others.

The space between words.

When a space is left between two words, it is called a noun-noun construction.
➞ see main article on spacing

References