Fuller \Full"er\, n. [AS. fullere, fr. L. fullo. See {Full}, v. t.] One whose occupation is to full cloth. {Fuller's earth}, a variety of clay, used in scouring and cleansing cloth, to imbibe grease. {Fuller's herb} (Bot.), the soapwort ({Saponaria officinalis}), formerly used to remove stains from cloth. {Fuller's thistle or weed} (Bot.), the teasel ({Dipsacus fullonum}) whose burs are used by fullers in dressing cloth. See {Teasel}.