1.  ticking(n = noun.event) tick - a metallic tapping sound; "he counted the ticks of the clock"
is a kind of sound
has particulars: ticktock, tictac, tocktact
Derived forms verb tick₂, verb tick₁

2.  ticking(n = noun.artifact) - a strong fabric used for mattress and pillow covers;
is a kind of cloth, fabric, material, textile
Derived form verb tick₃

   A strong, closely woven linen or cotton fabric, of which ticks for beds are made. It is usually twilled, and woven in stripes of different colors, as white and blue; -- called also ticken. [1913 Webster]

ticking, n. a stout usu. striped material used to cover mattresses etc.

Etymology:
TICK(4) + -ING(1)

ticking bomb