Here are some possible words:
backlash
backwash
badmouth
bakshish
becometh
begorrah
behemoth
bequeath
besmirch
bigmouth
birdbath
blackish
blandish
bleakish
blimpish
blockish
blondish
blowfish
bluefish
bonefish
brackish
brainish
brandish
brassish
brattish
bringeth
broadish
broguish
brownish
bullrush
credenza
Golgotha, gardenia
turmeric
calthrop
outbreak
Continue?
twinkled
One example of an 8-letter word ending with "ing" is "starting." It refers to the act of beginning something or initiating a process.
actually activity acrimony
Falluja -as in Falluja, Iraq
* symbolic * sporadic * sadistic * sardonic * specific
vacancy validity voracity velocity