Similar words
Gunst
Gefallen is a favor, a specific helpful act; Gunst is favour in the broader sense of goodwill or being in someone's good graces.
Similar in other languages
Spanish
merced
Close — a favor relates to mercy/favour.
Practice
1 What does Gefallen mean?
favor
2 Fill the gap: Kannst du mir einen ___ tun?
Full sentence: Kannst du mir einen Gefallen tun? (Can you do me a favor?)
3 Which fingerprint chart matches Gefallen?
Gefallen: neutral register, common frequency, general domain, neutral connotation.