بچه (bacce/бача) is the Persian word for “child”. Despite what might also be your first instinct, it appears to have no etymological connection to “bachelor”. It is used in the name of two controversial practices, “Bacha posh” (dressing a girl up as a boy) and “Bacha bazi” (pederasty, which as we all know is the fault of the Greeks). The latter concept is culturally important enough that when one looks up “bachcha” in an Uzbek-English dictionary, this is what one finds:
(dial.) child, boy; dancing boy.
Bear in mind that the headword is merely “bachcha”, the same word that means merely “child” according to Persian dictionaries, and indeed can refer to girls (دختربچه). One presumes that “dancing boy” does not refer to any boy who dances, but specifically to a certain variety of “professional dancer”. Indeed I have never heard an Uzbekistani use “bachcha” (I don’t tend to discuss pederasty very much) in polite conversation, which implies its use for children who are not sexualised objects is in fact taboo, “bola” being preferred in its stead. One hardly needs to compare the implications of “bolajonlik” to those of “bachchabozlik/bachavozlik” (google them if you don’t believe me).
And yet according to Nişanyan, بچه gave the Turks of Turkey the word “paşa”, whose implications are as non-sexual as one would hope for a term adults use to refer to children. The oft-quoted folk etymology is “padişah”, but Nişanyan insists that this is “baseless” (or rather he insists that it lacks a “dayanak”, which is a TDK-ism whose Cental Asian equivalent would and ought to be “dayanç” in Turkey), although this naturally raises questions about the Kazakh usage of “патша” (“patşa”) for “king”.
As long as we’re on the subject of words for children that Turks use, in addition to the many delightful (and disproportionately male) native Turkic terms for children, there are some which Turks have borrowed: the Arabic ولد (with somewhat demeaning associations, In Uzbek this word is used to mean “bastard, rascal”), as well as the widespread idea that its plural (أولاد) ought to refer to “progeny” or “descendents”, even if it is only a single child.
You are now armed with more information than you had several minutes ago. Use it wisely.