Grammars of Georgian (e.g. in Hewitt 1995, Aronson 1991) typically mention that certain verbs lack part of their paradigm. However (and this becomes especially apparent after reading Tschenkéli 1958), whether one wants to construe this as defectiveness depends on where one wants to draw the line between different lexemes. Strictly speaking, the verbal TAM paradigm is divided into three 'series' or 'screeves', present, aorist and perfect, which are (potentially) morphologically and syntactically distinct. Cross-cutting this is the distinction between four 'conjugations' or verb classes, which differ from each other morphologically and in their argument structure.
| conjugation 1 | conjugation 2 | conjugation 3 | conjugation 4 | |
| present series | present series | present series | present series | |
| aorist series | aorist series | aorist series | aorist series | |
| perfect series | perfect series | perfect series | perfect series |
Verbs are then said to be missing e.g. their perfect series, or aorist series. This way of speaking of things treats 'verb' as defined by the individual conjugation classes. But the same root may be inflected according to different conjugations, and it is not clear (at least to me) that these then constitute distinct lexemes. Thus, if a given root is missing forms within one conjugation, it may have them when inflected according to another.
Aronson, Howard. 1991. Modern Georgian. In: The indigenous languages of the Caucasus ; Volume 1: Kartvelian languages. Delmar: Caravan Books. 219-312.
Hewitt, B. George. 1995. Georgian: a structural reference grammar . Amsterdam/Philadelphia: John Benjamins.
Tschenkéli, Kita. 1958. Einführung in die Georgische Sprache (volume 1: Theoretischer Teil). Zurich: Amirani.