The term 'was lost in thought' can be summarized by two crossword solutions: 'mused' (5 letters) and 'mooned' (6 letters). Both words refer to a state of deep contemplation or reflection, often characterized by a distant gaze and lack of awareness of one's surroundings. To muse is to ponder or consider something deeply, while to moon is to stare off into the distance in a dreamy or absent-minded manner.