We found 3 dictionaries that define the word on the back of an envelope:

General (3 matching dictionaries)

1. on the back of an envelope: Cambridge Advanced Learner's Dictionary

▸ Words similar to on the back of an envelope ▸ Usage examples for on the back of an envelope ▸ Idioms related to on the back of an envelope ▸ Wikipedia articles (New!) ▸ Words that often appear near on the back of an envelope ▸ Rhymes of on the back of an envelope ▸ Invented words related to on the back of an envelope