lib

Latin līber meant simply "free" — a free person, not a slave. In Roman society this was one of the most loaded words you could use: your whole legal status hung on whether you were līber or not. From this single adjective grew an entire vocabulary of freedom.

The noun līberta(s) gave English liberty — the abstract state of being free, the right to act without being controlled. The adjective passed straight through as liberal: originally "worthy of a free person" (a "liberal education" was the kind a free citizen, not a laborer, received). Because a free, secure person can afford to be open-handed, liberal also came to mean "generous," and the abstract noun liberality is exactly that generosity. Centuries later, in politics, liberal picked up its modern sense: someone who favors individual freedom and reform — a "liberal" in the party sense.

The Romans also made a verb: līberāre, "to set free." That verb is the engine behind the action words. liberate and liberation describe the act of freeing — a prisoner, a city, a movement. "Women's liberation," "the liberation of Paris" — always someone or something being released from control.

Now the surprise. deliver does not look like it belongs here, but it is the same verb wearing a disguise: Latin dē- (thoroughly, away) + līberāre = dēlīberāre in Late Latin, "to set completely free, to release entirely." Trace its meanings and you can still feel the "release":
- deliver a package — you release the goods into someone's hands (hand over);
- deliver a baby — you free the child from the womb (the midwife "delivers" it);
- deliver a speech — you let the words out, release them to the audience;
- deliver us from evil — set us free from danger.

Every one of these is a kind of "letting go." The cargo-and-courier meaning we use today is just the most common branch of an old tree whose root is "make free." The noun delivery then covers the same spread: a delivery of parcels, the delivery of a baby, the delivery of a line on stage.

Two cousins worth knowing: liberate/libertine are pure līber (a libertine is someone who has freed himself from moral restraint), and Liberia was literally named "land of the free."

Finally, the traps. library is NOT from this root — it comes from Latin liber meaning "the inner bark of a tree" that was written on, hence "book." And equilibrium comes from lībra, "a balance/scales." They share letters with līber "free" but nothing else. When you see lib-, ask: is it about freedom (liberty), about books (library), or about balance (equilibrium)? Only the first belongs to this family.