1 boundless

2 vast and obscure

1 vast and indistinct

2 perplexed

3 bewildered

4 at a loss

1 uncertain

2 remote

3 distant and indistinct

4 vague

1 (of mist, snow, floodwater etc) a vast expanse of whiteness

1 blankly

2 vacantly

3 at a loss

1 the hazy dusk of twilight (idiom)

1 sea of bitterness is vast (idiom)

1 at a loss (idiom)