Lanche vs. petisco
While both lanche and petisco translate to "snack" in English, they serve very different cultural functions in Portuguese-speaking countries. Lanche implies a small meal to satisfy hunger or a specific type of food (a sandwich), while petisco refers to finger foods eaten for pleasure in social settings.
Lanche
A1The word lanche typically refers to an afternoon snack eaten between lunch and dinner to curb hunger. It can also specifically mean a "sandwich" (like a hamburger or a sub). It is a functional mini-meal, often consisting of coffee, juice, fruit, yogurt, bread, or cake.
Eu sempre sinto fome na hora do lanche da tarde.
(I always feel hungry at the time of the afternoon snack.)
Minha mãe preparou um lanche saudável para eu levar para a escola.
(My mother prepared a healthy snack for me to take to school.)
Vamos naquela lanchonete comer um lanche de frango.
(Let's go to that snack bar to eat a chicken sandwich.)
Você prefere jantar ou apenas tomar um lanche hoje?
(Do you prefer to have dinner or just have a light snack today?)
Petisco
B1The word petisco refers to bite-sized appetizers, finger foods, or tapas. These are savory treats meant to be shared socially, usually accompanied by alcoholic drinks (like beer or wine) or soda. The goal is grazing and socializing rather than filling up on a full meal.
Nós pedimos cerveja e alguns petiscos no bar.
(We ordered beer and some appetizers at the bar.)
Azeitonas, salame e queijo são meus petiscos favoritos.
(Olives, salami, and cheese are my favorite finger foods.)
Ele adora preparar petiscos para assistir ao jogo de futebol.
(He loves preparing snacks to watch the soccer game.)
O restaurante serve vários petiscos de frutos do mar.
(The restaurant serves several seafood tapas.)
Summary
To choose the right word, consider the context: use lanche if you are talking about a sandwich or a mini-meal consisting of coffee and bread to satisfy hunger (like a packed lunch or tea time). Use petisco if you are talking about savory finger foods aimed at nibbling while drinking and socializing with friends.