noun
unreleased stop; applosive
Technical term in phonetics for a stop consonant produced without an audible release burst, such as the final /p/ in English 'stop' when unreleased.
日本語の「がっこう」の「っ」は内破音として実現することが多い。
The small 'tsu' in Japanese 'gakkou' is often realized as an unreleased stop.