wantonly

Concise Oxford English Dictionary © 2008 Oxford University Press:
wanton/ˈwɒntən/

▶adjective

• 1 (of a cruel or violent action) deliberate and unprovoked.

• 2 sexually immodest or promiscuous.

• 3 literary growing profusely; luxuriant.

  ■ lively; playful.

▶noun archaic a sexually immodest or promiscuous woman. ▶verb archaic or literary

• 1 play; frolic.

• 2 behave in a sexually immodest or promiscuous way.

– derivatives
wantonly adverb,
wantonness noun.

– origin ME wantowen ‘rebellious, lacking discipline’, from wan- ‘badly’ + OE togen ‘trained’ (rel. to team and tow1).