mid-13c., fille, "a full supply," from Old English fyllu "fullness, 'fill,' feast, satiety," from Proto-Germanic *full-ino- "fullness" (source also of Old High German fulli, German Fülle, Old Norse fyllr), noun of state from *fullaz "full" (see full (adj.)). Meaning "extra material in music" is from 1934.
Middle English reke "smoke, fumes; steam, vapor," from Old English rec (Anglian), riec (West Saxon), "smoke from burning material," probably from a Scandinavian source such as Old Norse reykr, Danish rǿg, Swedish rök "smoke, steam."
These are reconstructed to be from Proto-Germanic *raukiz (source also of Old Frisian rek, Middle Dutch rooc, Old High German rouh, German Rauch, Icelandic reykr "smoke, steam"), from PIE *reug- "to vomit, belch;" also "smoke, cloud."
The sense of "stench" is attested 1650s via the notion of "that which rises" (compare reek (v.)). Century Dictionary (1891) marks the word "Obsolete, archaic, or Scotch." According to OED, "As the word has chiefly survived in northern use the palatalized form reech is comparatively rare." A c. 1250 document refers to the period March-April as Reke-fille "the misty month."
early 14c., "little headband," from Old French filet "thread, filament; strip, ligament" (12c.), diminutive of fil "thread" (see file (v.1)). Sense of "cut of meat or fish" is from late 14c., apparently so called because it was prepared by being tied up with a string.
late 15c., "one who fills," agent noun from fill (v.). Meaning "something used to fill" is from 1590s. Specifically of food products by 1901.
c. 1600, "to bind with a narrow band," from fillet (n.). Meaning "to cut in fillets" is from 1846. Related: Filleted; filleting.