akcento

One rule, no exceptions. Esperanto stress falls on the penultimate syllable of every word, always: ta-BLO, a-MI-ko, es-pe-RAN-to, ak-CEN-to. There is no list to learn and no dictionary to consult, which is one of the quiet reasons the language is easy to read aloud from cold. The full account, and what poets do with it, is in poetic Esperanto: because every unelided word ends unstressed, verse can only rhyme feminine unless a poet elides the final -o, and kor' for koro is how a line is made to land hard.

The three senses, and one thing akcento is usually not. It covers the stress on a syllable, the accent somebody speaks with, and the written mark over a letter. That third sense is real and the dictionaries carry it, but it is worth knowing that Esperanto has its own word for its own hats: the marks on ĉ ĝ ĥ ĵ ŝ ŭ are supersignoj, sometimes affectionately ĉapeloj. Call them akcentoj and you will be understood; call them supersignoj and you will sound like somebody who has read the ĥ question, where those six letters get argued over properly.

Building on it. Akcenti is to stress a syllable or to emphasise a point, akcentita is stressed, and senakcenta describes speech with no noticeable accent - a thing nobody has, in any language.