Similar words
frasco
termo specifically means a thermos flask; frasco is more general, a small container or jar.
Similar in other languages
Portuguese
frasco
frasco is the Portuguese word for the same thing — both mean "flask."
Practice
1 What does termo mean?
flask
2 Fill the gap: Llevo café en un ___.
Full sentence: Llevo café en un termo. (I carry coffee in a flask.)
3 Which fingerprint chart matches termo?
termo: neutral register, common frequency, general domain, neutral connotation.