Natural; animal: the opposite of spiritual.Like a beast in form or nature; animal.Like a beast in conduct or instincts; brutal; filthy; coarse.Befitting a beast; unfit for human use; filthy; abominable.Nasty; disagreeable: as, beastly weather.Synonyms Brutal, Bestial, etc. See brute.In the manner of a beast; filthily; abominably.