円蓋[engai] cupola
掩蓋[engai] cover(ing)
火蓋[hibuta] apron of a gun
蓋し[kedashi] perhaps
蓋然性[gaizensei] probability

口蓋[kougai] palate
臭い物に蓋[kusaimononifuta] looking the other way
上げ蓋[agebuta] trap door
天蓋[tengai] canopy

開け閉て[aketate] opening and shutting
開閉[kaihei] opening and shutting
基地閉鎖[kichiheisa] (military) base closing
自閉症[jiheishou] autism
腸閉塞[chouheisoku] intestinal obstruction

閉まる[shimaru] to be shut
店閉まい[misejimai] closing up shop
閉ざす[tozasu] to shut
閉じる[tojiru] to close (e.g. book, eyes, meeting, etc.)
閉込める[tojikomeru] to lock up