buccal / buckle 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. 👇
buccal: (adjective) of or relating to or toward the cheek. (adjective) lying within the mouth. (adjective) oriented toward the inside of the cheek.
buckle: (noun) fastener that fastens together two ends of a belt or strap; often has loose prong. (verb) fasten with a buckle or buckles. (verb) fold or collapse.
buccal: b·y·UW·k·ah·l
buckle: b·AH·k·ah·l
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)