adverb
aimlessly; without purpose; at random
Describes moving, wandering, or acting without a clear goal or destination. Often used with verbs of motion like 歩く or 旅する.
彼は当てもなく街を歩いた。
He walked aimlessly through the streets.
当てもなく電車に乗ってみた。
I got on a train without any particular destination in mind.
ぶらぶら emphasizes a leisurely, strolling manner, while 当てもなく focuses on the lack of purpose or destination.
無目的に is a more formal, direct way to say 'aimlessly', whereas 当てもなく is a common, natural expression.
From 当て (aim, goal) + も (inclusive particle) + なく (adverbial form of ない, 'not having'). Literally 'without even an aim'.