What is an incomplete construct (murakkab nāqis)?

Join two or more words so that together they give a meaning, and you have a مُرَكَّب (murakkab). When the meaning stops short of complete, the murakkab is نَاقِص (nāqis).

The test is the one that decides a sentence. The speaker cannot stop there, and the listener is left waiting.

كِتَابُ عَلِيٍّ (kitābu 'aliyyin), “Ali’s book”, is two words joined, and together they say more than either says alone. But the listener is still waiting to hear what about Ali’s book. Nothing has been said of it yet.

A construct like this is not a sentence, and the grammarians do not call it جُمْلَة (jumlah). It is a phrase.

A murakkab nāqis is named after how the parts of the construct relate to each other.

كِتَابُ عَلِيٍّ (kitābu 'aliyyin) joins a thing to its owner. This is called مُرَكَّب إِضَافِيّ (murakkab idāfī). رَجُلٌ شُجَاعٌ (rajulun shujā'un), “a brave man”, joins a thing to its description. This is called مُرَكَّب تَوْصِيفِيّ (murakkab tawsīfī).

Like most Arabic grammar terms, نَاقِص (nāqis) was taken from everyday speech and then given one precise technical sense.

In everyday Arabic it means lacking — a thing short of what it should have.

وَزْنٌ نَاقِصٌ (waznun nāqisun) — “short weight”

In Arabic grammar it describes a murakkab whose meaning falls short, so that it stands as a phrase and not a sentence.