Absolute (ABST) and construct (CSTR) form (or state) of nouns is a morphosyntactic phenomenon found in Semitic, Berber (Mettouchi 2014), and in some African languages like Wolof: it generally consists of head nouns bearing a marker in the case of nominal modification, in which case the noun is said to take the CSTR form. Outside of modification, the ABST form is used. In a typological survey, Creissels (2017), makes different cross-linguistic observations based on a larger sample of genetically unrelated languages: There are no cross-referencing features of the modifier on the noun; the CSTR form can co-occur with other marked features of the noun (e.g. number); cross-linguistic variation exists in the type of modifiers that trigger the CSTR form and in the morphological nature of the CSTR marking. This presentation includes data from Kibiri, an underresearched severely endangered language spoken by 32 people at Kikori district in the Gulf province of PNG. It forms, with Porome [prm], the Kibiri-Porome isolate group. Ongoing analysis shows that Kibiri exhibits such a feature and it confirms the above-mentioned typological observations: no cross-referencing features of the possessor on the noun; the CSTR form co-occurs with number of the head noun; adjectives, numerals and other modifiers trigger CSTR form; the morphological means of the CSTR form are suffixation, final vowel alternation, stem suppletion, etc. More interesting is the fact that two CSTR-marked nouns have been lexicalized as verbs and that the phenomenon interacts with word order. The talk will be based on already existing descriptions of CSTR form from other languages with a comparison with new data from original fieldwork on Kibiri.