Reconstruction:Proto-Slavic/aščerъ

Perhaps from *a- (“no-”) +‎ *ščerъ with second element possibly meaning:

• “agile, nimble” in reference to the reptilian locomotion of lizards. Akin to Proto-Slavic *skorъ (“speedy, quick”), possibly *xъrtъ (“hound”), *čьrtъ (“demon”). Further cognate with Lithuanian skėrỹs, skėrẽlis (“locust”), Latvian šķírgaîlis (“lizard”).
• “fur, pelt” in reference to the hairless skin of lizards. Akin to Proto-Slavic *skora (“hide”) and cognate with Albanian shqarr (“marten”). Similar meaning is attested in secondary Russian я́щер (jáščer, “rough leather”). A variation of this hypothesis (due to Potebnja) proposes that the prefix *a- is instead a clipping of unattested *aхъ (“prickly, scrubby”), cognate with Sanskrit आखु (ākhú, “mole”), possibly Ancient Greek σκίουρος (skíouros, “squirrel”).

In either case, possibly cognate with Sanskrit आश्चर्य (āścarya, “wonderful, marvelous”) (according to Machek).

Per Brückner, may alternatively reflect *askъ (“burrow, hollow”) +‎ *-erъ in view of some rare forms with alternative ending (in *-elь, *-jurъ). Effectively meaning “burrow-dwelling animal” (even though lizards are not known to dig their lairs).

*aščerъ m[1]

1. lizard
2. salamander
3. (by extension) sort of skin inflammation (mycosis, scleroderma, aphtha, sore throat, etc.)

• *jaščerъ
• *guščerъ (in South Slavic)

• *aščerica, *aščerъka

• *aščerь, *aščelь (“amphibian”)
• *jaščurъ (“lizard, reptile”)

• East Slavic:
  • Old East Slavic: ꙗщеръ (jaščerŭ)
    • Old Ruthenian: ꙗ́щеръ (jáščer)
      • Belarusian: я́шчар (jáščar)
      • Ukrainian: я́щір (jáščir)
    • Russian: я́щер (jáščer)
• South Slavic:
  • Old Church Slavonic: ащєръ m (ašterŭ), ащєра f (aštera)
  • Bulgarian: я́щер (jášter) (archaic)
  • Serbo-Croatian: (archaic, dialectal)

    Cyrillic script: ја̏штер

    Latin script: jȁšter

• West Slavic:
  • Czech: ještěr
  • Kashubian: wieszczór
  • Polabian: vistăr
  • Polish: jaszczur
  • Old Slovak: jašter
    • Pannonian Rusyn: ящур (jaščur)
    • Slovak: jašter, (dialectal) jaśčur
  • Sorbian:
    • Lower Sorbian: jašćeŕ

• Vasmer, Max (1964–1973) “я́щер”, in Oleg Trubachyov, transl., Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), Moscow: Progress
• Trubachyov, Oleg, editor (1974), “*aščerъ”, in Этимологический словарь славянских языков [Etymological dictionary of Slavic languages] (in Russian), numbers 1 (*a – *besědьlivъ), Moscow: Nauka, page 81
• “skėrỹs”, in Lietuvių kalbos etimologinio žodyno duomenų bazė [Lithuanian etymological dictionary database], 2007–2012