Avocado is a good example of Hobson-Jobson — altering a borrowed foreign word for easier pronunciation. Avocado is from Spanish aguacate, but the Spanish g is hard for English speakers to say. And the Spaniards altered it from the Nahuatl word ahuacatl!
English borrows a lot of words from other languages, but if they're too awkward for English speakers to pronounce, we change the sounds a bit. Another example is tickety-boo, meaning "perfectly fine," which comes via Hobson-Jobson from the quickly spoken Hindi phrase Thik hai, babu, meaning "it’s fine, sir." Hobson-Jobson itself is an alteration of the main words in the Arabic phrase ya Hasan, ya Husayn, a lament for the martyred grandsons of Muhammad that is used in plays commemorating the event.