発泡 is read as はっぽう (happou) and means foaming.
はっぽう
happou
はっぽうすちろーる
styrofoam
はっぽうせい
effervescence
はっぽうしゅ
happōshu
はっぽうわいん
sparkling wine
はっぽうぽりうれたん
foamed polyurethane
はっぽうざい
foaming agent
はっぽうせいしゅるい
carbonated alcohols
びはっぽう
slightly sparkling
こうはっぽうざい
anti-foaming agent
ばね
spring
はってん
playing around (sexually; esp. of a male homosexual)
ほったん
origin