c. 1400, "that which fills or fills up," verbal noun from fill (v.). Dentistry sense is from 1848. Filling station attested by 1915.
filling (adj.)
"calculated to fill or satisfy," 1620s, present-participle adjective from fill (v.).
Filipino
fill
filler
fillet
fill-in
filling
fillip
filly
film
film noir
film-maker