1997 Chevy Cavalier what's this dash light mean?

1997 Chevy Cavalier 114000 miles

I have a 1997 Cavalier with a dash light that comes on after I've driven for a while. It's on the left side of the speedometer and has a wavy horizontal line like fluid I suppose (I'm a woman, forgive the description) and has an arrow pointing down over it. I'm sure it's telling me that I have low fluid somewhere but I can't determine where. I thought coolant, but when I open the cap it's full. I'm afraid to drive to far and be left sitting beside the road. Any help would appreciated.
Georgie