I. ˈ ̷ ̷| ̷ ̷ adjective
Etymology: slap (II)
: marked by roughness and impetuousness of manner or method
businessmen of the slap-bang, horn-blowing, bluff, good-natured … kind — Edna Ferber
slap-bang … production methods — K.B.Butler
II. adverb
: with excessive force, haste, and usually noise : precipitately
yachts and … chasers ran slap-bang at 16 knots into a convoy — Springfield (Massachusetts) Republican