This is the 15050th most frequent Russian word.
поженились
"Got married."
The verb 'поженились' is in the past tense and indicates that the event of marriage took place.
Они поженились прошлой весной.
They got married last spring.
'Пожениться' is in its infinitive form, describing the decision to marry in the future.
После учебы они решили пожениться.
After their studies, they decided to get married.
Here, 'поженитесь' is in the future tense, showing an action that may happen.