### Clue: Short time secured by reserve in box, say (5)
### Answer: SHRUB 
 ### Explanation: Definition: box, say
 HR(short for "hour", a period of time) **contained in**(secured by) SUB(short for a substitute;a reserve player).
Answer: An example of which;say, is the box, a dense slow-growing shrub, used for hedges, borders, and garden mazes.