fennel / phenyl 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. 👇
fennel: (noun) any of several aromatic herbs having edible seeds and leaves and stems. (noun) aromatic bulbous stem base eaten cooked or raw in salads. (noun) leaves used for seasoning. (noun) fennel seeds are ground and used as a spice or as an ingredient of a spice mixture.
phenyl: NA
fennel: f·EH·n·ah·l
phenyl: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)