This is the 13991st most frequent Polish word.
poszli
"Poszli" means "they went" in English.
The word 'poszliśmy' is derived from the root 'iść' (to go) and indicates that the subject (we) performed the action of going in the past tense.
Poszliśmy do kina wczoraj wieczorem.
We went to the cinema yesterday evening.
Here 'poszli' represents the action of the brothers (they masculine) going somewhere, specifically applying to a group of males in the past tense.
Poszli bracia szukać zgubionego psa.
The brothers went to look for the lost dog.
In this example, 'poszliście' relates to the action of 'you plural' going, highlighting past tense (perfective action) performed by a group addressed informally.