аѥсова

Old Novgorodian

By surface analysis, *аѥ (*aje) +‎ *совати (*sovati) +‎ -а (-a), literally “testicle-shover”. Derived from Proto-Slavic *aje (“egg”) with preservation of the original initial *a- without iotation + *sovati (“to shove”).^[1] First attested in c. 1140‒1160.

аѥсова • (ajesova) m^[2]

(vulgar, hapax) wanker; dickhead, fucker, horndog (an insult)
- c. 1140‒1160, Берестяная грамота № Ст. Р. 35 [Birchbark letter no. St. R. 35]‎^[2], Staraya Russa:
  … ѧкове брате еби лежѧ ебехото аесово
  … jękove brate ebi ležę ebexoto ajesovo
  … Yakov, brother, fuck lying down, you lustful testicle-shover.

nouns

^ Anikin, A. E. (2007) “аєсова”, in Русский этимологический словарь [Russian Etymological Dictionary] (in Russian), issue 1 (A – аяюшка), Moscow: Manuscript Monuments Ancient Rus, →ISBN, page 106
^ Zaliznyak, Andrey (2004) Древненовгородский диалект [Old Novgorod dialect]‎^[1] (in Russian), 2nd edition, Moscow: Languages of Slavic Cultures, →ISBN, page 710