御食い初め[okuizome] weaning ceremony
為初め[shisome] outset
為初める[shisomeru] to begin to do
仮初[karisome] temporary
業界初[gyoukaihatsu] the industry's first ...

月初め[tsukihajime] beginning of month
最初[saisho] beginning
初めに[hajimeni] to begin with (used as an introduction)
初めは[hajimeha] at first
手初めに[tehajimeni] at first

ガリア戦記[gariasenki] History of the Gallic Wars
ゲリラ戦[gerirasen] guerrilla warfare
セールス戦略[seerususenryaku] sales strategy
ベトナム戦争[betonamusensou] Vietnam war
マーケティング戦略[maaketingusenryaku] marketing strategy

悪戦[akusen] hard fighting
悪戦苦闘[akusenkutou] hard fighting
一回戦[ikkaisen] first game
一戦[issen] battle
厭戦[ensen] war weariness

挑む[idomu] to challenge
挑戦[chousen] challenge
挑戦者[chousensha] challenger
挑撥[chouhatsu] provocation
挑発的[chouhatsuteki] provocative

挑戦状[chousenjou] written challenge
戦いを挑む[tatakaiwoidomu] to challenge (a person) to a fight
戦争挑戦国[sensouchousenkuni] warmonger
挑戦いかに[chousenikani] How dare you!
戦争挑発[sensouchouhatsu] aggression