and; such things as; what with
Listing particle used in the pattern AやらBやら to give non-exhaustive examples, often implying a mixture or variety. Can carry a nuance of being overwhelmed or bothered by the listed items.
机の上には本やらノートやらが散らかっている。
Books, notebooks, and such are scattered on the desk.
引っ越しで服やら家具やらを運ぶのに一日かかった。
It took a whole day to move clothes, furniture, and the like during the move.
Expresses uncertainty or vagueness, often attached to a question word or a noun. Common in the pattern とやら to indicate hearsay or a vague recollection.
See also: とやら
彼は何やら慌てて出て行った。
He rushed out for some reason or other.
Books, clothes, and who knows what else were scattered around the room.
There was a call from someone called Tanaka or something.
He seemed to be lost in thought about something or other.
What with crying and laughing, it was quite a day.
とか is the common, casual listing particle for giving examples, while やら suggests a more chaotic or unwelcome mix of things.
か attached to a question word expresses simple uncertainty (何か, いつか), while やら (何やら, いつやら) adds a vaguer, more musing tone.
だの lists examples with a critical or complaining tone, whereas やら is more neutral though it can still hint at being overwhelmed.
Derived from the classical auxiliary verb や (expressing doubt or question) combined with the particle ら (indicating plurality or vagueness). The exact historical development is uncertain, but it has been used as a listing and uncertainty particle since at least the Edo period.