aˈttenuating,ppl.a. [f. as prec. + -ing2.] Making thinner; in Med.= attenuant a. 1616Surfl. & Markh.Countr. Farm 552 Such as haue need of a fine and attenuating nourishment.1822Burrowes Cycl. II. 550/1 Caryophyllaceæ..are reckoned astringent, attenuating and detersive.