taru-adjective, adverb taking the 'to' particle
vast; boundless; wide and empty
Describes a physical space that is overwhelmingly large, open, and empty, often with a sense of desolation. Used in literary or formal contexts.
空々漠々とした荒野がどこまでも続いていた。
A vast, empty wilderness stretched on endlessly.
taru-adjective, adverb taking the 'to' particle
vague and hazy; unclear and boundless
Describes something abstract, such as a plan, idea, or feeling, that is vague, unfocused, or lacking clear boundaries. Also literary.
彼の将来の計画は空々漠々としていて、具体性に欠ける。
His future plans are vague and hazy, lacking concreteness.
漠然 is a more common word for 'vague' or 'obscure', used in everyday language, while 空々漠々 is a literary yojijukugo emphasizing boundlessness and emptiness.
広大 means 'vast' or 'extensive' in a neutral, descriptive way, without the literary or desolate nuance of 空々漠々.
A yojijukugo composed of 空 (empty, sky) and 漠 (vague, desert-like), reduplicated for emphasis. The exact historical derivation is uncertain, but the combination conveys an image of boundless emptiness.