join together, link, incorporate
拼 centers on bringing separate things into a single unit: joining together, linking, or incorporating parts into a whole.
拼 combines 扌 (hand) with 并, which likely contributes both sound and the idea of combining or putting side by side. The exact historical development is uncertain, but the structure suggests a hand action of joining.
The hand radical 扌 beside 并 suggests using your hands to bring things together, like linking pieces into one unit.
For ホウ, imagine a hand joining two pieces with a loud 'hou' sound as they snap together: hou -> ホウ.
Tongyong Pinyin; former official Taiwanese romanization system