Source : Webster's Revised Unabridged Dictionary (1913)

Obstructive \Ob*struct"ive\, a. [Cf.F. obstrictif.]
   Tending to obstruct; presenting obstacles; hindering; causing
   impediment. -- {Ob*struct"ive*ly}, adv.

Source : WordNet®

obstructively
     adv : in an obstructive manner; "he acted very obstructively when
           we tried to carry out our project" [syn: {hinderingly}]