I'll raise my hand as a signal. ✬

The signal turned green. ✬

Don't cross the road while the signal is red. ✬

The signal was red. ✬

The car's left-turn signal was broken. ✬

Tom dialed Mary's number and got a busy signal. ✬

Tom often forgets to use his turn signal. ✬

Tom has been getting a busy signal every time he tries to call Mary. ✬

The ship flashed a distress signal. ✬

Stand by for my signal. ✬