From Longman Dictionary of Contemporary Englishmanicman‧ic /ˈmænɪk/ adjective 1 informalMP behaving in a very anxious or excited way She seemed slightly manic. Mortimer continued to shoot, a manic grin on his face.2 medicalMP relating to a feeling of great happiness or excitement that is part of a mental illness
Examples from the Corpus
manic• There was a manic air to the way he ate his steak and kidney pie.• It was a wide, manic and utterly humourless rictus.• Williams is a comedian with a lot of manic energy.• Lee Evans' as a manic human wind-up toy.• Thus Wish veers dizzily from gleeful whimsy to cosmic angst; from unconfident extroversion to manic introspection.• In manic or bipolar depression, bouts of depression alternate with periods of excessive elation or mania of similar length.• Events unfolded with a manic slowness at first.• Let us take a forceful manic who is displaying and functioning on 500 arbitrary units of life force.• The manic with 500 units of directed purpose has been cleared.Origin manic (1900-2000) mania 