time
immediately
At a glance
In short
All four are Rabbinic Hebrew, none of them in Tanach, and all four mean "immediately." Teikef is immediately after, one thing hard on the heels of another (it also means physically pressed close together). Miyad is straightaway, literally "from hand," which suggests the readiness of what is already in your hand. Le'alter is on the spot; some commentators explain the word as a contraction of al atar. Otyom appears once, in the Mishnah (Niddah 2:2), and its derivation is disputed. Rabbi Emmanuel Chai Ricci takes it as an abbreviation of a Hebrew phrase. Rabbi Betzalel Ronsberg prefers the view of Rav Hai Gaon, the Aruch, Rashi and Rashba, who all hold it is a Greek loanword, and the Ancient Greek εὐθέως, eutheos, means "immediately."
Distinctions
Teikef (תיכף)
Carries both senses at once: "closely pressed together" in space and "rapidly succeeding each other" in time. Two objects set right beside one another and two events falling right after one another take the same word. This is Rabbi Klein's governing idea, which he says may help shed light on some of the set: the joining of space and time, an idea the Maharal of Prague (1525-1609) had already expressed long before the space-time continuum entered physics in the last hundred years, is reflected in Hebrew, where some words (and even some English ones) carry both a spatial and a temporal meaning; olam (the whole world / forever) and lifnei and acharei (before and after, in place and in time) work the same way.
Miyad (מיד)
Hyper-literally "from hand," which suggests a link between time and space. What sits in a man's hand is the most readily transferred thing there is, passing straight to the next hand without an interval; so too an event that follows the one before it with nothing in between. Rabbi Klein adds a thought of his own: he once thought the English "off-hand" might be related to miyad, so that "I don't remember off-hand" would mean "I don't immediately remember."
Le'alter (לאלתר)
Some commentators, among them Rabbi Yishaya Pick-Berlin (1725-1799) and Rabbi Yaakov Emden (1697-1776), explain it as a portmanteau of al atar, "on the spot." Again a word for place doing duty for time. Some Jews have the custom of greeting one another on the first night of Rosh Hashanah with l'shanah tovah tikaseiv v'seichaseim le'alter l'chaim tovim u'l'shalom.
Otyom (אותיום)
Appears once in the Mishnah, Niddah 2:2, and clearly means "immediately thereafter"; some argue the vocalization should really be evteos.
- Rabbi Emmanuel Chai Ricci (1688-1743), in his commentary to the Mishnah, takes it as an abbreviation of a Hebrew phrase spelling out the halachic definition of "immediately" in that sugya.
- Rabbi Betzalel Ronsberg (1762-1821) disagrees, pointing out that it does not square with the Gemara's conclusions about that definition, and prefers Rav Hai Gaon (in the commentary to Niddah ascribed to him), Sefer HeAruch, Rashi (Yoma 6a, Kerisos 17b) and Rashba (Toras HaBayis 7:3), who all write that otyom is actually a Greek word. Indeed, the Ancient Greek εὐθέως, eutheos, means "immediately."
Sources
Rabbi Reuven Chaim Klein, "Forthwith in the Fourth Dimension," What's in a Word?, Ohr Somayach, 16 September 2017.
Cited in the essay: Mishnah Niddah 2:2; Rashi to Yoma 6a and Kerisos 17b; Rashba, Toras HaBayis 7:3; Rav Hai Gaon to Niddah; Sefer HeAruch; the Maharal of Prague; Rabbi Yishaya Pick-Berlin; Rabbi Yaakov Emden; Rabbi Emmanuel Chai Ricci's commentary to the Mishnah; Rabbi Betzalel Ronsberg.