1 weaponry

2 weapons

3 arms

1 sky

1 to gain

2 to get

3 to acquire

1 empty

2 air

3 sky

4 in vain

1 air

2 atmosphere

1 a worthless piece of paper (idiom)

1 spare the rod and spoil the child (idiom)

1 the people are gone and the place is empty (idiom)

2 the sight of a deserted place brings old friends to mind

3 the place is deserted

4 the birds have flown

1 to judge sb by appearances (idiom)

1 empty-handed (idiom); fig. not receiving anything