寔 is not used independently in modern Chinese. In classical texts it means 'truly / this' and is interchangeable with 实; the set phrase 寔繁有徒 'such people are indeed many' preserves it. It also appears as a personal-name character.
register
Classical / literary only — seen in old texts and idioms, not in everyday speech; modern equivalent is 实.
The roof radical 宀 caps the character, the same 'roof / under cover' element seen in 实 and 家. Here it mirrors the structure of 实, the standard character 寔 stands in for.
Under the roof sits 是 (to be; this), giving the sound — shì to shí — and reinforcing the 'this / indeed' meaning, since 是 itself can mean 'this'. So it works as both sound and faint meaning hint.
No stroke data for 寔; the glyph shown is your device font, so component strokes can't be highlighted.
