gest

The Latin verb gerere meant "to carry, to bear" — but also, by extension, "to carry out, to conduct, to wage." A Roman general didn't just hold a war in his hands; he gerere bellum — "carried on" the war. So from the very start this root pointed in two directions at once: physical carrying, and the figurative carrying-on of an activity. Its past participle was gestus, which is where the gest- spelling in English comes from. Most of the family branches off by adding a prefix that says what is carried and in which direction.

Start with the body and the stomach:

- dis- (apart) + gerere → digest: to "carry apart" — to break food down into pieces the body can absorb. The same image works for ideas: you digest a difficult chapter by breaking it into manageable parts. The noun digest (a condensed summary) is the printed version of the same act — a big text broken down and carried into a small space.
- in- (in) + gerere → ingest: to "carry in" — to take food or data into a system.
- con- (together) + gerere → congest: to "carry together" too much into one place, so nothing can move — a clogged road, a stuffed-up nose. Hence congestion.

Now the abstract, social senses:

- sub- (from below) + gerere → suggest: to "carry up from underneath" — to slip an idea up into someone's mind without stating it outright. You don't hand them the conclusion; you carry it quietly up to them. From here come suggestion, suggestive (carrying a hidden, often improper, hint), and suggestible (easy to slip ideas into).
- gesture: a manner of carrying the body — the way you move your hands and shoulders to carry meaning across to someone. Stretch that into a verb and you get gesticulate, to throw the whole body into carrying a message.
- gestation: the body carrying a pregnancy. Figuratively, a plan in gestation is being carried, growing quietly before it's born.

Then the members that keep the harder -ger- spelling and pull the meaning toward conducting and heaping:

- bellum (war) + gerere → belligerent: literally "war-waging" — someone conducting a fight, and so, by character, aggressive and spoiling for one.
- ex- + aggerare (to heap up, itself from agger 'a pile') → exaggerate: to keep heaping more onto the pile until it stands higher than the truth.
- register came a longer way, through Latin regerere "to carry back, record" and Medieval Latin regestrum — the book where entries are carried back and written down. To register is to have your name carried into the official book.

A warning about a look-alike: guest has nothing to do with this root. It comes from Old Norse gestr / Germanic roots meaning "stranger, visitor" (the same family as host and hospitable), and only looks like it belongs here. Pure spelling coincidence. And jest drifted: it began as gesta, "deeds, exploits" (things carried out, from gerere) — the tales a minstrel told — and slid from "story" to "funny story" to "joke."