One of the frustrations of working with Tscheremissiches Wörterbuch is that some Mari items are labeled
< Tschuw. or
< Tat., but the exact source is not specified and sometimes one has to dig a little to determine the original Chuvash or Tatar word.
A case in point is MariE tolašem W talašem ‘sich bestreben, eilen, irgwendwie zu tun versuchen’. This is marked as a Tatar loanword in TschWb, and the word is clearly of Turkic origin since it has a causitive derivational form MariE tolaštarem W talaštarem. I turned to my dictionary of literary Kazan Tatar, the Татарско-русский словарь (Казань: Мәгариф, 2007), and found a phonetic match: талашу. However, the meanings ‘сспориться, скандалить, переругиваться’ of this verb and its derivational forms were not close enough to the Mari verb to satisfy.
If my Tatar dictionary doesn’t help for a Turkic loanword in Mari, the next stop is a Chuvash one. Ashmarin’s Thesaurus Linguae Tschuvaschorum contains a verb corresponding to the Tatar one and almost certainly a borrowing of it, namely tulaş, and the first meanings mentioned are the same as for the Tatar: ‘беситься, злиться, грызться’. However, buried deeper down in the entry is the meaning we’re looking for:
возиться, стараться. This is an understandable extension of the Turkic root tal-, the basic meaning of which is ‘to force; to take by force’.
Thus Mari and Chuvash preserve a meaning of the Tatar word that seems to have died out among Kazan Tatars. Interestingly, Russian too borrowed this Tatar word dialectally and uses it in a similar sense, or at least it did in the 19th century: a verb талашиться ‘суетиться, толочься, метаться’ is attested from the Tambov region in the Толковый словарь Даля, compiled by Vladimir Ivanovich Dal’ and published in 1863–1866.
Incidentally, had I carefully examined the Mari–English Dictionary instead of basing myself solely on Tscheremissiches Wörterbuch, then I could have figured out this etymology more quickly, because one of the meanings of MariE lit. толашаш is ‘to quarrel, to squabble, to bicker’, and that meaning is not found in TschWb. However, the Mari–English Dictionary, being a general literary-language reference and not a dialect dictionary, does not list the origin of the item, and I wonder if the word in that meaning was found only in Eastern Mari communities under heavy Tatar influence before the rise of the literary language, and only the meaning ‘try hard, strive’ is pan-Mari.