) A damp squid (a damp squib)
2) On tender hooks (on tenter hooks)
3) Nip it in the butt (nip it in the bud)
4) Champing at the bit (chomping at the bit)
5) A mute point (a moot point)
6) One foul swoop (one fell swoop)
7) All that glitters is not gold (all that glisters is not gold)
8) Adverse to (averse to)
9) Batting down the hatches (batten down the hatches)
10) Find a penny pick it up (find a pin pick it up)