Similar words
helada
helada specifically means a "frost" as a weather event, a freeze; escarcha is the physical frost that forms on surfaces, the visible ice crystals.
Similar in other languages
French
givre
givre is the French word for the same thing — both mean "frost."
Portuguese
geada
geada is the Portuguese word for the same thing — both mean "frost."
Practice
1 What does escarcha mean?
frost
2 Fill the gap: Hay ___ en el suelo.
Full sentence: Hay escarcha en el suelo. (There is frost on the ground.)
3 Which fingerprint chart matches escarcha?
escarcha: neutral register, common frequency, general domain, neutral connotation.