@asena_great
Bayat: In old Turkic "t" was also plural suffix, therefore its more possibly means "rich, noble people."
Bayandur: I think its also related to word "Bay" rich, noble
Chavuldur: It might be related to raiding, but "dar" suffix is Persian.
Eymir: I have no guess about that.
Yüregir: .In earliest sources, its recorded as "Üregir", so possibly not related to yürümek.
Bügdüz: I think not mean
I would not want my tribe to be named "Big Salt"
plus t to d and k to g evolution is happened later in Oghuz languages, so its originally "Tuz" , itz not Bügduz anyway, its "tüz" , ü is a diferent sound.
Kayı: Koy(village) is a foreign word and "i" is a Persian suffix, "put" is "Koy", I think "Kaymak" is still the most possible thing.
Yazır: May be related to writing, but I think its more likely related to another meaning of "Yazmak" "Spreading out" , "Laying" do you have that verb ? It can be also related to summer.
Karkın: Kahar is Arabic, I think its coming from a verb we dont know.
Çepni: I can't think of anything for this, for me its sounds foreign.
Avshar: Its also sounds foreign, I remember reading something about Iranian "Fshar" "extracted".
Çarıklı: %90 related to shoe.
Pecheneg: These guys are actually a different tribe, Pecheneg tribe inside of the Oghuz is just a group of them who is defeated and joined Oghuz, some historians says its related to Baca/Bacanak "brother in law" but Im not sure.
Alayuntlu: Dude Yunt meant horse, so its means "those with reddish horses), but in Qashgarli its recorded as "Ula Yontlu" may be Ula is Great. A far fetched guess is, it might be "those with great carved stones"