pearl / purl are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
pearl: (noun) a smooth lustrous round structure inside the shell of a clam or oyster; much valued as a jewel. (verb) gather pearls, from oysters in the ocean.
purl: (noun) gold or silver wire thread. (noun) a basic knitting stitch. (verb) knit with a purl stitch. (verb) edge or border with gold or silver embroidery. (verb) embroider with gold or silver thread.
pearl: p·ER·l
purl: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)