Can refer to a lump of something, often used in a figurative sense.
La clota en la herida hizo que el médico decidiera suturarla de inmediato.
The clot in the wound made the doctor decide to stitch it up immediately.
La clota en la herida indicaba que debía ir al médico de inmediato.
The clot in the wound indicated that he should go to the doctor immediately.