Meaning : In a careless or reckless manner.
Example :
The shelves were put up slapdash.
Synonyms : slapdash
Meaning : With heedless speed.
Example :
Yachts ran slap-bang into the convoy at 15 knots an hour.
Meaning : In a violent or sudden or noisy manner.
Example :
The pans fell slam-bang and woke the whole house.
Synonyms : slap-bang