vac·u·ous
adj.

1. Devoid of matter; empty.
2.

a. Lacking intelligence; stupid.
b. Devoid of substance or meaning; inane: a vacuous comment.
c. Devoid of expression; vacant.

3. Lacking serious purpose or occupation; idle.

pop
adj.

1. Of or for the general public; popular or popularized: pop culture; pop psychology.
2. Of, relating to, or specializing in popular music: a pop singer.
3. Of or suggestive of pop art: a pop style.

n.

1. Popular music.
2. Pop art.