conjunct

progressing melodically by intervals of a second

• “conjunct motion of an ascending scale”

bound in close association

• “conjunct influences”
• “conjunct ideas”

involving the joint activity of two or more

• “the attack was met by the combined strength of two divisions”
• “concerted action”
• “the conjunct influence of fire and strong wind”
• “the conjunctive focus of political opposition”
• “a cooperative effort”
• “a united effort”
• “joint military activities”