Not designing or planning. rare.

Of persons: acting in such a manner; unceremonious, unstudied. Now usually in negative sense: ungraciously or offensively casual or cool in manner…

Unpremeditated, impromptu; (also) casual, nonchalant, unceremonious, or curt in style or manner; = offhand, adj. Also occasionally as adv. (see…

(un-, prefix1 affix 4.)

Of persons, their character, actions, etc.: Actuated or characterized by impulse; apt to be moved by sudden impulse or swayed by emotion.

Of a person: tending to act instinctively, spontaneously, or expediently. Of an activity: done on the basis of practical experience rather than…