pulso

A clinical word, used clinically. The pulso is the beat of the arteries that the heart drives, felt at the wrist or the neck. Kalkuli la pulson is to take somebody's pulse, la pulso estas rapida or malrapida or neregula, and senpulsa means pulseless. This is one of the places where Esperanto's international vocabulary earns its keep: a doctor in any country reads the sentence without a dictionary.

The verb comes with it. Pulsi is to pulse or to throb, and it works on more than arteries: la maŝino pulsis, la muziko pulsis, pulsanta doloro for a throbbing pain. Pulsado is the pulsing considered as a process, and pulsobato is a single beat.

Two fences the English word forces on us. First, the pulses you eat, the lentils and beans, have nothing to do with this word; those are guŝofruktoj or simply fazeoloj kaj lentoj. English collapsed two unrelated Latin words, pulsus and puls, into one spelling, and Esperanto did not follow. Second, an electrical or signal pulse is an impulso, not a pulso, so a pulse of current and a pulse at the wrist are different words here even though the metaphor is obvious.

Where it sits in the body vocabulary. Koro the heart, sango the blood, arterio the artery, vejno the vein, spiro the breath. A kuracisto checks la pulso, la temperaturo kaj la spirado, which is a phrase worth having ready if you ever need a doctor abroad.