Within the vocabulary of Old Turkic, there are uncertainty about the etymological analysis of the words ıçgın- and örgin in both inscriptions and manuscripts, as well as in Old Uyghur and Karakhanid Turkic texts. The suffix {-n-} at the end of the word ıçgın- and {-n} at the end of the word örgin are detectable. Apart from this determination, there is a gap in Turcology regarding the root forms of these two words with verbs connecting root forms to {-n-} / {-n} suffixes also the second suffix that both words are understood to have. This second suffix seen in the structure of both words seems to be {-gI-} suffix. The suffix {-gI-} has an important place in the etymological explanation of the words ıçgın- and örgin. The existence of this suffix, which is not included in the etymology dictionaries prepared on vocabulary and word deriving of Old Turkic, seems inevitable when the words ıçgın- and örgin are examined in depth. Because the verb örgi- in the south tenth line of the Şine Usu inscription, which is witnessed in the explanation of the word örgin, has a key role in understanding this situation. In this study, firstly, the meanings of the words ıçgın- and örgin will be emphasized with sample testimonies from the vocabulary of Old Turkic. Then, the etymology suggestions for the relevant words will be addressed from a critical point of view. After that the root forms that are thought to be the source of these two words and the suffixs that the words take will be try to explained. In the last part of the article, structural and semantic appearance of the suffix {-gI-}, which was not found in the determinations of researchers such as Clauson, Gabain, Erdal, Orkun and Tekin, will be emphasized in the light of the results obtained.