Is the word costumes the same in Brazilian and European Portuguese?

Yes

The word "costumes" (the plural of costume) is identical in spelling, grammar, and primary meaning in both Brazilian and Continental Portuguese. In both dialects, it refers to "customs," "traditions," or "habits." The only significant difference is in pronunciation:

• Vowels: In Brazilian Portuguese, the "o" is typically more open ([kos]), whereas in Continental Portuguese, it is more closed or reduced ([kuʃ]).
• Sibilants: In Brazilian Portuguese, the "s" sounds are usually dental or alveolar ([s]), whereas in Continental Portuguese, the "s" at the end of a syllable or word is pronounced as a "sh" sound ([ʃ]).

Brazilian Portuguese Examples

1. Os costumes do Brasil são muito diversos. (The customs of Brazil are very diverse.)
2. Ele tem o costume de malhar de manhã. (He has the habit of working out in the morning.)
3. É um costume de família fazer churrasco aos domingos. (It is a family custom to have a barbecue on Sundays.)
4. Não é o meu costume comer carne. (It is not my habit to eat meat.)
5. Aprendemos os costumes da região durante a viagem. (We learned the customs of the region during the trip.)

Continental Portuguese Examples

1. Os costumes de Portugal são muito diversos. (Portuguese customs are very diverse.)
2. Ele tem o hábito de treinar de manhã. (He has the habit of training in the morning.)
3. É uma tradição de família fazer um churrasco aos domingos. (It is a family tradition to have a barbecue on Sundays.)
4. Não estou habituado a comer carne. (I am not used to eating meat.)
5. Aprendemos os costumes da região durante a viagem. (We learned the customs of the region during the trip.)