deobstructive adjective 1noun 1forms 3 adjective1 •Having the effect of deobstructing (clearing a passage, etc. of obstructions).In the weaker and finest bodies Manna may be sufficient, […] or my Deobstructive powder, which I have observed hath done singularly well. — 1672 noun1 •Something that has the effect of deobstructing.[…] by setting up currents through the kidneys […] it [turpentine] has acted as a renal deobstructive. — 1885 formsdeobstructives · more deobstructive · most deobstructive