### Clue: See writer's Swift having name for Lilliput's leader (7)
### Answer: IMAGINE 
 ### Explanation: Definition: See
 I'M(contraction of "I am" as is "writer's" a contraction of "writer is", and "I" is the self-referential pronoun for the writer) + "agile"(swift;quick in movement) **with **"n"(abbrev. for "name") **replacing**(having … for) **the 1st letter of**(…'s leader) "Lilliput".
Defn: … in one's mind.