Planetology is the scientific study of planets.

The plangency of the bells filled the air.

The plangent sound of the bell echoed mournfully.

The carpenter used a thick plank to build the table.

The planking of the old ship was in dire need of repair.

Plankton are tiny organisms that float in the water and serve as a food source for many marine animals.

The plant louse is damaging the crops.

I love cooking with plantain.

I saw a plantain growing by the roadside.

I have plantar fasciitis, which causes pain in the bottom of my foot.