This is the 17440th most frequent Polish word.
zaspokajając
"Zaspokajając" means "satisfying" or "fulfilling" in English.
In this sentence, 'zaspokajając' describes the action of fulfilling someone's needs as a participle modifying how 'On pomagał' is carried out.
On pomagał ludziom, zaspokajając ich potrzeby.
He helped people by fulfilling their needs.
Here, 'zaspokajając' indicates the manner in which the girl's action of spending time is serving to satisfy her curiosity.
Dziewczyna spędzała godziny w bibliotece, zaspokajając swoją ciekawość.
The girl spent hours in the library, satisfying her curiosity.
In this example, 'zaspokajając' shows the purpose behind the action of eating, which is to fulfill his hunger.