An Etymological Dictionary of Astronomy and Astrophysics

1a) (v.) To → beat, to → vibrate.

1b) (v.) Physics: To → emit  → particles or → radiation  → periodically in short → bursts.

2a) (n.) Physics: A variation of a quantity whose value is normally constant. The essential characteristics of a pulse are: a → rise, a finite → duration, and a → decay.

2b) (n.) Physics: A single, abrupt emission of particles or radiation. See also → pulse counter, → pulse nulling, → pulse width, → pulsed laser, → precursor pulse.

Etymology (EN): M.E., from M.Fr. pous, from L. pulsus “a beat,” p.p. of pellere “to push, drive,” from PIE *pel- “to shake, swing.”

Etymology (PE): Tapidan “to beat, throb,” Mid.Pers. tapīdan “to be anguished; to suffer; to grow hot, to be hot,” variant tâftan, tâpidan “to stir up, to excite; to shine;” tâp “fever;” Av. tap- “to be hot, to grow hot,” tafnah-, tafnu- “fever, feverish heat;” cf. Skt. tap- “to spoil, injure, damage,; to suffer; to give out heat, to be hot,” tápati; L. tepere “to be warm;” PIE base *tep- “warm.”