File. Rasp, smooth, finish; place on file; polish; perfect, refine, improve.
Ant. Roughen, jag, acuminate, denticulate, barb, notch, cusp.
Fill. Make full, fill up; pervade, occupy; dilate, expand, stretch, distend; store, supply, furnish, replenish, stock; satisfy, content, sate, satiate, cloy, pall; occupy, hold, fulfil, perform; become full, be filled; gorge, appoint, glut; stuff; rise; swell, grow, increase.
Ant. Exhaust, drain, dissatisfy, deprive, stint, vacate; misappoint; subside, ebb, evaporate, shrink, diminish.
Filter. Strain, ooze, percolate, exude, transude; refine, distil, leak; purify, cleanse, depurate, defecate, clarify.
Ant. Muddle, disturb, befoul, thicken.
Filthy. Dirty, nasty, foul, defiled, unclean, squalid; impure, corrupt, gross; dingy, unsanitary, unwholesome.
Ant. Pure, sweet, healthy, clean, sanitary, wholesome.
Final. Latest, last, eventual, ultimate; decisive, conclusive, definitive; terminal; definite, developed.
Ant. Initiative, open, progressive, continuous, incipient, current, unconcluded, inchoate, inaugural, nascent, rudimental.