Ship was a word which could refer to a boat (PROSE: No Room [+]Loading...["No Room (short story)"]) or a spacecraft.
The First Doctor described the TARDIS as a ship and would refer to it as "the ship". (TV: An Unearthly Child [+]Loading...["An Unearthly Child (TV story)"]) Meeting the First Doctor just prior to his regeneration, the Twelfth Doctor was amused to hear him still referring to the TARDIS as such. (TV: Twice Upon a Time [+]Loading...["Twice Upon a Time (TV story)"])
Ruby Sunday once described the TARDIS as "an incredible ship". (PROSE: Who's the Doctor? [+]Loading...{"page":"6","1":"Who's the Doctor? (short story)"})