dense, heavy, thick
black, blue, grey/gray, white, etc.
billowing
acrid, choking
stale
the smell of stale cigarette smoke on your clothes

wood
cigar, cigarette, pipe, tobacco
second-hand
Hundreds of people die each year as a result of exposure to second-hand smoke (= smoke from other people's cigarettes, cigars, etc.).

cloud, column, haze, pall, plume, puff, spiral, wisp
We sat drinking in a haze of cigarette smoke.
The witch disappeared in a puff of smoke.

belch, belch out, blow, emit
The car ahead was belching out black smoke.
Don't blow smoke in my face!

exhale, inhale
be wreathed in
She sat there wreathed in cigarette smoke.

belch, billow, come, curl, drift, pour, rise
Blue smoke curled up from her cigarette.
Smoke rose into the sky.

fill sth
hang
A pall of yellow smoke hung over the quarry.

clear
When the smoke cleared we saw the extent of the damage.

plume, ring
I taught myself to blow smoke rings.

signal
bomb, grenade
alarm, detector
inhalation
machine
The club had a smoke machine and laser show.

break (informal, esp. AmE)
I was taking a smoke break outside.

go up in smoke
The barn went up in smoke.

full of smoke
thick with smoke
The bar was thick with stale tobacco smoke.