jar, pot
瓿 centers on a type of container: a jar or pot, typically made of earthenware.
瓿 combines 咅 (likely a phonetic component) with 瓦 (earthenware), suggesting a type of pottery vessel. The exact historical development is uncertain.
The left side 咅 looks like a container with a lid and a spout, and the right side 瓦 means earthenware. Together they form a jar or pot made of clay.
For ホウ, imagine a potter shaping a jar and saying 'hold' as they mold the clay: hold -> ホウ, and the jar takes form.