Baby's plaything (6)
I believe the answer is:
rattle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">baby's plaything</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rattle that I've seen before include "Toy for baby or football fan" , "Infant's toy" , "not to compose" , "Lively old song - Shake, . . . . . . and roll" , "Noisy toy and snake" .)