The term kick drum is essentially synonymous with bass drum. It tends to be used more to describe synthesized bass drums, usually generated by drum machines, than their acoustic counterpart. It is arguably one of the most important parts of a drum machine, and the Roland TR-808's kick drum defined a lot of music of its era, due to the fact that it was very punchy and had a knack of of sounding very powerful with the right speakers.
It's worth noting that you can still get fairly good percussion sounds, including kick drums, using regular synthesizers if they are sufficiently tweakable, such as the Roland SH-101.