Last letter = First Letter, min 3 syllable word chain

consternation

naturalistic

conifer

relentless

standoffish

heliocentric

coconut

tympani (or timpani, take your pick)

-“BB”-

intriguing

gigantic

colossal

leviathan

ninety-eighth

horticulture

excruciating

government

tenacious

seventy-seven

norovirus

sleeplessness