A gap, interruption, or uncontrolled shift in a chain of thought resulting in a lull, pause, and/or blank stare during oral communication and sometimes involving the loss of short term memory.
Everyone at the meeting waited for Jim's response as he finally snapped out of his odd gaze into an unseen abyss. "Sorry", he said, "I just had a brainfart, what were we talking about?".
Adj: The act of pretending to conduct an orchestra while classical music plays, often in a grandiose and unrealistic fashion. An iconic mimed gesture similar to the Sad Violin, Call Me, He's Drunk, et al gestures. maestrobation, maestrobator
As Stravinsky's Firebird Suite neared it's stirring climax, Jim raised his arms and began to maestrobate.