In the Lithuanian language, persons are named by simple words and formations. The latter are divided into the categories of derivation according to their derivational meaning. The categories of derivation involve synonymous formations, i.e., derivative synonyms, and some formations are coherent in variance relation (they are derivative variants).
The article aims to analyse the categories of derivation of synonymous conjugate personal names. The methods of derivational and semantic analysis, as well as calculation, were applied in the present research. The article discusses 1179 nominal personal names (out of these formations 338 rows of derivative synonyms and derivative variants were formed) collected from LKŽe, LKŽ, Volumes 1 and 2. After analysis of the empirical material, the following conclusions have been drawn: the formations of conjugate personal names were grouped into five categories of noun derivation: names of possessors of nominal characteristics (baldininkas, -ė – baldžius), names of persons according to profession (akmenininkas, -ė 1 / akmeninykas, -ė / akmeninkas, -ė / akmenykas, -ė – akmenkalis, -ė / akmenkalys, -ė – akmentašys, -ė), names according to origin (names of persons according to their place of origin and place of residence (adutiškėnas – adutiškietis, -ė); names of children according to their parents (antrasūnis – pasūnis – posūnis)), names according to gender differences (bernėnė – bernienė 1), names of collective nouns (bernynė – bernava – bernija). Only derivatives with suffixes and endings belong to the categories of noun derivation, but often persons are named by using derivatives with prefixes and compounds. Therefore, not only derivatives with suffixes and endings but also derivatives with prefixes and/or compounds belong to some rows of derivational synonyms (derivational variants). A big part of synonymous conjugate formations is composed of compounds (atlapaširdis, -ė – atviraširdis, -ė). These derivational synonyms (derivational variants) are not included in other traditional categories of derivation.