加 add

as in, "Add a CAR to my garage. "

The rapper's strong mouth added power to the struggling music label.

join ★★★☆☆
参 (admit defeat / visit) + 加 (add) = 参加 (join)

to join a group, or participate in something

unfounded, pointless ★★☆☆☆ CCW
加 (add) + 減 (decrease) = いい加減 (unfounded, pointless)

unfounded or groundless. Not a lie exactly, but someone who is just bullshitting, talking without saying anything meaningful or definite. Also means, working in a haphazard, hit-or-miss fashion.

an increase ★☆☆☆☆ NP
増 (increase) + 加 (add) = 増加 (an increase)