Definition from Wiktionary, the free dictionary
- Present participle of think.
1918, W. B. Maxwell, chapter 5, The Mirror and the Lamp:
- He was thinking; but the glory of the song, the swell from the great organ, the clustered lights, […], the height and vastness of this noble fane, its antiquity and its strength—all these things seemed to have their part as causes of the thrilling emotion that accompanied his thoughts.
- I'm thinking about inventing a new perpetual-motion machine.