aspen /ˈæspən/adjective 4noun 2forms 3 adjective4 •Pertaining to the aspen tree. •(no longer used) Tremulous, trembling.And then poore Aspen wretch, neglected thou / Bath'd in a cold quicksilver sweat wilt lye / A veryer ghost than I […]. — 1631 •(no longer used) Resembling an asp in some way •(no longer used) wagging, gossiping. noun2 •A poplar tree, especially of section Populus sect. Populus, of medium-size trees with thin, straight trunks of a greenish-white color.Above a certain elevation, the aspens gave way to scrubby, gnarled pines. •The wood of such a tree; usually pale, lightweight and soft.She claimed that aspen was the only "proper" material from which to make a wicker basket. formsaspens · more aspen · most aspen